








.4* 



^ ^ 
W 



%*0* Off 


















iS* <^ ' 














7 « A y "^ 



*. ...... * ■ c ^-y >-., 







5> . oL'sLr* * V 








1, '£' ^ A 










A 6* *o, *7^T* A. 




0' 



o" o, 



*«°o 




*oV" 




















,* '^o< • 







%•— 'A— .V" 



A* 



INTRODUCTION 



TO 



"WITH 

^■ftrACTI'CAIi <VC^STX©XS 

DESIGNED FOR 

BEGINNERS IN THE SCIENCE. 

FROM THE 

LATEST AND MOST APPROVED AUTHORS. 

TO WHICH IS ADDED 

& THctionaxy of Teirms. 



BY JOHN RUGGLES COTTING, 

LECTURER ON NATURAL AND EXPERIMENTAL PHILOS- 
OPHY, CHEMISTRY AND BOTANY. 



BOSTON: 

PUBLISHED BY CHARLES EWER.. ..NO. 51, CORNHIIX 

May, 1822. 







c** 



DISTRICT OF MASSACHUSETTS. ...to wit : 

District Clerk's Office. 

BE IT REMEMBERED, That on the E ! ghteenth day of May, A. D. 1822, 
in the forty sixth Year of the Independence of the United States of America, 
JOHN RUGGLES COTTING, of the said District, has deposited in this Office, 
the Title of a Book, the right whereof he claims as Author, in the words follow- 
in?, to wit : 

M An Introduction to Chemistry, with Practical Questions : des'gned for Be- 
ginners l n the Science. From the latest end most approved Authors. To which 
i r added ', A Dictionary of Terms* by John Ruggles Cotting, Lecturer on Natural 
and Experimental Philosophy, Chemistry and Botany," 

la conformity to the Act of the Congress of the Unittd States, entitled " An 
Act for the encouragement of Learning, by securing the Copies of Maps, Charts 
and Book3,to the Authors and proprietors of such Copies, during the times there* 
in mentioned :" and also to an Act entitled, " An Act supplementary to an Act, 
entitltd An Act for the encouragement of Learning, by securing the Copies of 
Maps, Charts and Books, to the Authors and Proprietors of such Copies during 
the times therein mentioned ; and extending the Benefits thereof to the Art&of 
Designing-, Engraving and Etching Historical, and other Prints/ 1 

TV a tv n«rT5 S Clerk of the District 
JNO, W. DA\ IS. | of Massachusetts. 



true &■ greene Printers. 



PREFACE. 



J. HE science of chemistry is considered as a part of a 
polite and liberal education for both sexes, and is taught 
in most of the literary institutions of our country. Its util- 
ity and the interest which it is calculated to excite, can- 
not fail to recommend it to the attention of every inquis- 
itive mind. It is so intimately connected with the phys- 
ical sciences in general, that no one of them can success- 
fully be. cultivated entirely independent of it 

Chemistry is not confined to one department of nature 
it takes a wide range through all the works of creation, 
and subjects all material bodies to its laws. " The solid 
matters comprising the terrestrial mass of the globe we 
inhabit; the aqueous fluids which penetrate its cavities 
or float on its surface ; the more gaseous fluids which 
surround this ponderous mass ; the agencies of heat, light 
and other fleeting substances expanded through the 
mighty space, are subjects upon which the chemical phi- 
losopher may dwell with infinite profit and delight." 

Chemistry extends itself into the minute concerns of 
active life, and is the fostering hand of innumerable im- 
portant arts, and the various discoveries made in the 
science are so many acquisitions to those arts. 

The science is no longer, as formerly, confined to the 
laboratory of the artist, but it ranks among the first in 
philosophical research. It has been enriched, and is 
continually undergoing improvements by philosophers, 
in every part of Europe. Works on cheHstry are daily 



IV. PREFACE. 

issuing from the press, which are excellent in them- 
selves, and have a tendency to advance the student in 
the knowledge and improvement of the science. But 
there are few that are calculated, in every respect, for 
beginner?. 

Tiie Conversations on Chemistry, by Airs. Bryan, is a 
very useful and popular work, and has been through many 
editions both in Europe and America. The subjects are 
treated in a very pleasing and familiar manner. Great 
obligations are due to the amiable authoress for the good 
she has done to the cause of the science. But the exper 
diency of adapting this as an elementary work, at the 
present time is questioned by many instructors, as great im- 
provements and discoveries have been made in the science 
since that work was written ; many subjects are there 
inserted which have no relation whatever to this coun- 
try, and the colloquial manner of treating the subjects 
necessarily occupies a great portion of the book, which 
might otherwise be appropriated to subjects of more in> 
portance. 

Works which treat of the rudiments of chemistry 
should be perspicuous, as it embraces a variety of sub- 
jects, and those, owing to the revolutions which the sci- 
ence is continually undergoing,arc too often involved with 
other matters, not immediately connected with first princi- 
ples. The consequence of which is, the student finding 
many objects arresting his attention, at once, all equally 
gratifying and attractive, looses sight of those elements, 
by which only, a permanent foundation can be laid. 
The author is no advocate for those who pretend to dis- 
play all the elegance of the temple of sjcience at once, in- 
to which the novice is introduced without preparation or 
ceremony, where idleness and industry are permitted to 
participate equally in the same rewards. He believes- 



PREFACE. V- 

that the candidate for excellence must proceed with cau- 
tion, perseverence and labour; that there is but one road 
to science, which at first is rugged, steep and difficult ; 
that as we advance, we acquire strength to encounter new 
difficulties, till finally we are qualified to relish the sub- 
lime beauties that await the persevering and industri- 
ous. 
We ought alwaj's to bear in mind the maxim, 

" Radix doctrinae amara fructus dulcis." 

An attempt has been made in the following work ; to 
bring the principles of chemistry into as small a compass 
as possible, and in a concise manner to exhibit the vari- 
ous subjects treated of by the most eminent chemical 
writers of the present day. 

The work is designed for beginners in the science, it 
became therefore, necessary to consult the interests both 
of the instructor and pupil. Few chemical works appear 
to have had this object in view. Authors have gone 
upon the supposition that the learner has already become 
acquainted with the elements, and is qualified to pursue 
it^ through all the intricate subjects, in the elaborate 
works of the present day, The consequence is, that ei- 
ther much time is lost in attempting to acquire a knowl- 
edge of the subject, or an aversion is contracted which 
ends in a total neglect of this useful and pleasing sci- 
ence. To obviate these inconveniences is the design of 
the author in the following pages ; whether he has suc- 
ceeded in his object, he leaves to a candid and impartial 
public to judge. 

With regard to imparting instruction, the author con- 
siders the plan he has adopted in this work as preferable. 
From long experience as an instructor, he feels a confi- 
dence in recommending the interrogatory method, as at- 
tended with the greatest utility. Questions at the end of 
1* 



VI. PREFACE. 

each chapter very much assist the learner ; and are like- 
wise conwnient for the instructor. Each question hav- 
ing a reference to a particular section, the answer may 
be easily committed to memory ; by which means the 
remarks of the author are readily comprehended, and 
much time saved, which is too often employed in turning 
over the leaves of a book, searching for the object, with- 
out a suitable guide to direct to the place ; this has a 
tendency to discourage rather than promote exertion. 

No pretensions, are made to originality in the follow- 
ing pages ; the work is a compilation. Neither is it de- 
signed to supersede any other. It is an introduction for 
the purpose of enabling students to commence with more 
pleasure and success those excellent works of Gorham, 
Thomson and Henry, which should follow this where a 
correct knowledge of the science is- desirable. In this 
compilation, recourse has been had to the works of va- 
rious chemical writers ; from which such extracts have 
been made as were thought necessary for an introduc- 
tion. If the subjects have been- properly arranged, and 
treated in a clear and perspicuous manner, the author 
will be rewarded by a consideration that he has per- 
formed an important task ; but this he dares not flatter 
himself that he has been able, fully, to accomplish. 

Some, perhaps, may object that remarks have beeit 
made, and passages inserted, which will not be easily 
understood by beginners, particularly in the chapter on 
Chemical Equivalents and the Atomic Theory ; but the au- 
thor is not conscious of inserting any thing which is not 
admitted by the most eminent of the European chemists, 
and which he is confident is conformable to the most ac- 
curate and rigid experiments, as well as to just theory. 
In examining the remarks of authors on the above sub- 
ject, for the. purpose of making a selection, being limited 



PREFACE. VII 

as to the size of the work, he found that he must either 
omit the articles altogether, or treat them agreeably to 
the plan of the authors from whose works they have 
been extracted. The atomic theory has been adopted r 
under various modifications, by most scientific men of the 
present day - r and most treatises of chemistry that have 
been published within the last ten years have a refer- 
ence to it, especially in the proportions of the different 
compounds -> the work, therefore, in his opinion, would 
have been very defective without some notice of the the- 
ory ; especially as one of the principal objects in the 
compilation was to prepare the pupil, by a knowledge of 
the first principles of the science, to enter upon fuller 
and more elaborate treatises, it became,, therefore, ne- 
cessary to treat the subjects not only in a concise man- 
ner, but conformably to the present exalted state of the 
science. Should any, however, be disposed to omit the 
chapter on chemical equivalents in the instruction o£ 
very young persons, it may be done without any derange- 
ment of the other parts. 

As some acquaintance with what is called Natural and 
Experimental Philosophy is necessary, previously to en- 
tering on the study of chemistry, the work is commenced 
with some of the rudiments of that science ; but brevity 
was absolutely necessary,, as the limits assigned to the 
work would not admit otherwise J> R> C, 

Boston, May 10th, 1822. 



TABLE OF CONTENTS 



4. 



3. 
cv. 

10. 
11. 
12. 
13. 

14. 
15. 

16. 
17. 
18. 
19. 
20. 
«1. 



Definition — General laws of Matters. Page 1 
Of Elements or simple bodies — Chemical 
attraction or affinity. - 9 
Theory of Atoms — Definite propor- 
tions — Chemical Equivalents. - 21 
Of Light— Caloric. - - - 38 
Continuation of Caloric. - 57 
Of Combined Caloric. - - 69 
Of Oxygen. - - - 79 
Of Azote orjN"itrog*en. - - - 80 
Of Hydrogen. * - - 83 
Of Sulphur. - - - 91 
Of Phosphorus. . - - -• 97 
Of Carbon. - - - 103 
Of Alkalies, - - - 111 
Of the Decomposition of Alkalies and 
Earths. - - - - 123 
On the Earths. - - - 133 
Of Magnesia — Alumina — Yttria — Glu- 
cina — Zirconia — Silica and Thorina. 145 
Of the Acids. - - -157 
Continuation of x\cids. 166 
Of Oxygen acids — Metallic, - 181 
Of Hydrogen Acids. - 186 
Acids of organic origin. - -192 
Of Chlorine. -.-'.- - 205 
Of Iodine. - - - 21a 



CONTENTS. IX. 

23. Of Salts in general. - - 216 

24. Of Electricity— Voltaic Electricity. - 220 

25. Of Metals. - - - 225 

26. Of Platinum— Gold— Silver— Palladium, 
Mercury. ... 238 

27. Of Copper— Iron— Tin— Lead— Nickel, 
Cadmium — Zinc. - - 251 

2S. Of Bismuth — Antimony — Manganese- 
Cobalt— Tellurium. 

29. Of Arsenic— Chromium, Molybdenum, 
Tungsten — Columbium — Selenium — 
Osmium. 273 

30. Rhodium — Iridium — Uranium — Titani- 
um — Cerium — Wodanium. - - 280 

31. Of Prussine or Cyanogen. - 234 

32. Of the nature and composition of Veg- 
etables. ----- 297 

33. Of Colouring matter — Decomposition of 
vegetables — Fermentation. - 306 

34. Continuation of Fermentation. - 316 

35. Of Vegetation. - - . c^B 

36. Of the animal department. - 343 

37. Of Respiration. ... 355 

38. On Animal Heat. - - - - 371 
A Dictionary of Chemical terms. 



ABBREVIATIONS 

AND 
USED IN THE FOLLOWING WORK. 



A small (o,) placed at the right hand, over a figure, 
ienotes degreess. 

F. at the right hand of a figure or figures, signifies Fa- 
enheit's thermometer. W. Wedgwood's pyrometer. 
I. Reaumer's thermometer, 

The sign + signifies that the figure to which it is pre- 
ixed is to be added. 

The sign — signifies that the figure which it precedes 
5 to be subtracted. When prefixed to degrees of the 
hermometer, it signifies that the temperature is so many 
egrees below zero. 

The sign X signifies that the figures between which 
t stands are to be multiplied together. 

The sign ■=- signifies that the figure preceding it is to 
e divided by the figure which comes after it. 

The mark =, called the sign of equality, signifies that 
be amount of the figures preceding are equal to the 
ucceding. 

:, : :. Signify that the figures between which they 
tand are proportional. 



DIRECTIONS FOR THE BINDER. 



Plate 1« Table of Chemical Equivalents, to face Title. 

2. To face page 46 

3. " ... - . 84 

4. " * 125 
Table of Metals. - - 233 

Plate 6. - - - 33g 



AN 

INTRODUCTION TO CHEMISTRY. 



CHAPTER I. 

Definition, <$*c. — General Laws of Matter. 

1. Chemistry is the science which investigates the 
combinations of matter, and the agencies of those gener- 
al forces whence these combinations are established or 
subverted. 

2. The subjects of Chemical inquiries are particles of 
matter, both the magnitude and form of which, and the 
distances within which they act upon each other, are 
wholly incapable on account of their extreme minute- 
ness to be estimated. 

Observation. Authors are not agreed with regard to 
the etymology of the word Chemistry ; it is generally 
thought to be of Arabian origin. 

3. Matter is the first principle of all natural things, 
from the various combinations and arrangements of which 
all bodies are formed. 

4. Substance is that which supports the different 
forms and appearances which are presented to our senses. 
In common language it means a distinct or definite por- 
tion of matter, whether solid or fluid 

Observation. The ward substance is compounded of 
the Latin preposition sub, under, and sto to stand ; it 
differs from matter, because it impll s a determinate fig- 
X 



^ INTRODUCTION 

ure, whereas, matter implies a more general and confus- 
ed idea of solidity and extension, without any regard to 
figure. 

5. Every kind of substance has certain characteristic 
properties, such as Solidity, Divisibility, Mobility and 
Inertia. 

6. By solidity or impenetrability, in common language 
is to be understood the property of not being easily 
separated into parts. 

Observation. If a piece of wood or stone occupy a 
certain space, they must first be removed before another 
body can be put in the place ; and though fluids, from 
their nature, appear at first to oppose such resistance, 
yet in proper circumstances they will be found to retain 
th 3 property in an equal degree. 

Exp. 1 . Put some water into a tube closed at one end, 
and insert into it a piston, a piece of wood, or metal, 
which exactly fit the bore of the tube ; then try to push 
the piston to the bottom, you will find it impossible, even 
by the force of the greatest pressure. 

Exp. 2. Pour the water from the tube, which will be 
empty as it is called in common language, but in reality, 
filled with atmospheric air. In attempting to push the 
piston to the further end, you will meet with the same 
resistance as before. 

7. We derive our idea of impenetrability from the 
resistance which we meet with in bodies, whether they 
be solid or fluid. 

8. Divisibility is that property by which matter is ca- 
pable of being divided into parts, and those parts separat- 
ed from each other. 

Observation. This divisibility is evident in bodies of 
sensible magnitudes ; w r e can never hy subdividing arrive 
at a part so small, but we can conceive that it consists of 



TO CHEMISTRY. 6 

two halves, but how far this actual division may be car- 
ried, whether to infinity or whether we should at last 
arrive at ultimate atoms, which from their nature, are 
not capable of subdivision, is a point not ascertained. 

The actual division of matter may be carried to an a- 
mazing extent,so as to approximate to our ideas of infinity. 

Illustration 1. A grain of gold is hammered by the 
gold beaters until it is the thirty thousandth part of a 
line in thickness, and will cover fifty square inches.— 
Each square inch may be divided into two hundred strips,, 
and each strip into two hundred parts v which may be 
seen with the naked eye ; consequently a square inch 
contains forty thousand visible parts, which multiplied by 
fifty, the number of square inches which a grain of gold 
will make, give two million parts, which may be seen 
with the naked eye. 

2. It has been calculated that sixteen ounces of gold, 
which, in the form of a cube, would not measure one 
inch and a quarter in its side,, will completely gild a 
quantity of silver wire sufficient to surround the globe. 

Exp. 1. Put into a quart of water a small piece of ni- 
trate of silver, lunar caustic, not larger than a common 
pin's head, it will impart a uniform milky colour to the 
whole liquor. 

Exp. 2. Into a pint of water put a small piece of sul- 
phate of copper, blue vitriol, not more than the one hun- 
dredth of a grain, it w r ill impart a sensible blue colour 
to the whole liquid. 

9. Mobility is that property by which bodies are ca- 
pable of being moved from one place to another. 

10. Inertia is a tendency which bodies possess of con- 
tinuing in the state in which they are placed, whether 
of rest or motion, unless prevented by some external 
force. 



4 INTRODUCTION 

Illustration 1 . A man standing in a boat while it is push- 
ed from the shore, will be in danger of falling backwards, 
but he will gradually acquire the motion of the boat, and 
if it be suddenly stopped, he will fall forwards, because 
his tendency will be to continue in motion. 

2. A man riding on full gallop, if the horse suddenly 
stop, is in danger of falling over the animaPs head, his 
tody having acquired the motion of the horse. 

1 1 . Space has no limits or bounds ; it consists of parts, 
which may be divided by the mind, but are not capable 
of actual separation. Its parts are only distinguished by 
bodies placed in them. 

12. Space is either absolute or relative. 

13. Absolute space is mere extension, it has no limits 
or bounds, and is itself immoveable. 

14. Relative space is that part of absolute space that 
is occupied by any body, and is compared by any part oc- 
cupied by any other body. 

15. Motion is either absolute or relative. 

16. Absolute motion is the actual motion which bodies 
possess, independant of each other, and only with regard 
to the parts of space. 

17. Relative motion is the degree and direction of 
the motion of one body compared with that of another. 

Illustration. By this imperceptible motion plants and 
animals grow, and the greatest number of compositions 
and decompositions throughout the globe take place. 

The temperature of bodies is constantly varying, con- 
sequently the particles must be in continual motion, in 
order to adapt themselves to the size of the body. 

18. Accelerated motion is, when the velocity of mo- 
tion continually increases. 

19. Retarded motion is, when the velocity continu- 
ally decreases. 



TO CHEMISTRY. » 

20. The velocity of uniform motion is estimated by 
the time employed in moving over a certain space, or by 
the space moved over in a certain time. 

21. To ascertain the velocity, divide the space run 
over by the time. 

22. To know the space run over, multiply the ve- 
locity by the time. 

23. In accelerated motion, the space run over is as 
the square of the time, instead of being directly as the 
time, as in uniform motion. 

Illustration. A body falling from a height, moves at 
the rate of 16 1-12 feet in a second of time, and acquires- 
a velocity of twice that, or 32 1-6 in a second. At the 
end of the next second it will have fallen 64 1-3 feet. — - 
The space being as the square of the times, the square- 
of 2 is 4, and 4 times 16 1-12 is 64 1-3. And so on. 

24. By velocity is meant what bodies would acquire 
if they should fall through a space where there was no 
air. Its resistance diminishes considerably their velocity 
in falling. Therefore in estimating the velocity of bodies, 
this circumstance must be taken into consideration. 

25. A body acted upon by one force will always move 
in a straight line. 

26. Bodies acted upon by two uniform forces, wheth- 
er equal or unequal, must form a straight Lne. But if one 
of the forces be not uniform, that is, either accelerating 
or retarding, the moving bodies will descr.be a curve line. 

Illustration. If a ball be projected from a cannon, it 
receives an impulse, which, if there were no res.stance 
from the air, and if it were not acted upon by gravity, 
would cause it to move always _n a straight Lne, bi-t as 
soon as it leaves tie mouth of the 6annen, gravity acta 
upcn it, and causes it 10 change its direction to that of a 
curve. 

1* 



b INTRODVCTION 

27. The momentum of a body is the force with which 
it moves, and is in proportion to the weight or quantity 
of matter, multiplied into its velocity. 

28. All bodies appear to possess attraction and repul- 
sion, the causes of which are totally unknown. 

29. There are various kinds of attraction, viz. the at- 
traction of cohesion ; of gravitation ; electricity ; mag- 
netism ; and chemical attraction or affinity. 

30. All the phenomena of chemistry arise from the 
attractions and repulsions exerted between the particle* 
of matter. 

31. Attraction of cohesion acts only at very small dis- 
tances. It is by this attraction that bodies preserve their 
forms, and are prevented from falling to pieces. 

Exp. 1. If two leaden bullets have a little scraped 
from each, so as to make them fit exactly ia those parts^ 
and they be put together with a. twist, they will adhere 
so strongly as to require a considerable force to separate 
them. 

Illustration. Hardness, softness, brittleness, ductility 
and malleability depend upon different modifications of 
the attraction of cohesion, 

32. When a body is in solution, and the attraction of 
cohesion is exerted suddenly, the particles unite indis- 
criminately and form irregular masses. But when it acts 
more slowly, the particles assume a particular arrange- 
ment, and form masses of regular figures. This is term- 
ed crystallization, and the regular figured masses are de- 
nominated crystals. 

33. Attraction of cohesion is the cause of the forms 
in which different bodies exist, and the regular figures 
which many of them assume. 

31. The attraction of gravitation or gravity is the 
tendency of bodies towards each other, which is exerted 
at all distances. 



TO CHEMISTRY. 7 

35. Every particle of matter in the universe gravi- 
tates towards every other particle. 

Illustration 1. By the attraction of gravitation, the 
heavenly bodies are retained in their orbits by their mu- 
tual action ; and by this, a stone dropped from a height 
falls to the surface of the earth. 

2. The planets and comets all gravitate towards the 
sun and towards each other as well as the sun towards 
them, and that in proportion to the quantity of matter in 
each. 

36. All terrestrial bodies tend towards a point, which* 
is exactly or very nearly the centre of the earth, conse- 
quently bodies fall every where perpendicular to the 
surface, and on opposite sides in opposite directions. 

Observation. If two bodies of equal quantity of mat- 
ter were placed at ever so great a distance from one 
another, and left at liberty in free space, and if there 
were no other bodies in the universe to affect them, they 
would fall equally swift towards one another, and would 
maet in a point which was half way between them at 
first. 

37. Gravitation decreases from the surface of the 
earth upwards as the square of the distance increases. 

38. We know nothing of gravity but by its effects, 

39. Electric attraction is that exerted by amber, seal- 
ing was, and some other substances when rubbed. 

Illustration. When amber and sealing wax are rubbed 
with a silk handkerchief, they attract feathers, dust, &c... 
from small distances. 

40. Magnetic attraction is that exerted by the load 
stone on iron. 

Illustration. The tendency of the needle to the pole 
is an instance of this attraction. 



INTRODUCTION 

PRACTICAL QUESTIONS. 
What is Chemistry ? 

What are the subjects of Chemical inquiries ? 
What is matter ? 
What is substance ? 

What are the characteristic properties of matter ? 
What is understood by solidity ? 
Do fluids possess solidity ? 
Illustrate this by experiment. 
How do we obtain our ideas of impenetrability ? 
What is divisibility ? 
Illustrate this. 

What experiment can you exhibit to confirm it, 
What is mobility ? 

What is inertia ? 

Illustrate it. 

What is space ? 

How is space divided T 

What is absolute space ? 

What is relative space ? 

How many kinds of motion are there ?' 

What is absolute motion ? 

What is relative motion ? 

Illustrate it. 

What is accelerated motion ? 

What is retarded motion ? 

How do you estimate the velocity of retarded motion f 

How do you estimate the space run over ? 

How is the space m accelerated motion ? 

Illustrate this. 

What is meant by velocity ? 

How will a body move that is acted upon by one force ? 

How if acted upon by two forces ? 

Illustrate it. 



TO CHEMISTRY. 9 

What is the momentum of a body ? 

What do all bodies appear to possess ? 

How many kinds of attraction are there ? 

From what do all the phenomena of Chemistry arise 2 

What is attraction of cohesion ? 

Illustrate this. 

What is the effect when the attraction of cohesion is 
exerted suddenly. 

What is the cause of the forms of different bodies ? 

What is the attraction of gravitation ? 

How does every particle of matter gravitate ? 

How is it with regard to the planets and comets ? 

How with regard to terrestrial bodies ? 

What would be the consequence suppose there were 
only two bodies in the universe, and they placed at a 
distance from each other ? 

How does gravitation decrease from the surface of 
the earth ? 

What do we know of gravity ? 

What is electric attraction ? 

Illustrate it. 

What is magnetic attraction ? 

Illustrate it. 



CHAPTER II. 

Of elements or simple bodies — Chemical attraction or 

affinity, 
1. In a Chemical sense, substances are divided into 
two kinds, viz. simple and compound, the former of 
which are sometimes called elements. 



ID INTRODUCTION 

2. Simple bodies are those which have not been sep- 
arated into others more simple, nor reproduced by arti- 
ficial means. 

Observation 1 . The ancients considered four substances 
as simple and uncompounded, which they denominated 
elements, viz. earth, air, lire and water. These have 
all been decomposed, and their constituent parts well as- 
certained. 

Observation 2. It would perhaps be presumption to as- 
sert that we are acquainted with any simple body Those 
which we now call elementary may hereafter be found 
to be compounded. Many that were supposed to be sim- 
ple twenty years ago have been decomposed, and their 
component parts clearly exhibited to the senses ; such 
are earths and alkalies, 

3. The term, elements, should be considered as denote 
ing the last term of the analysis, according to the present 
state of knowledge, 

4. The number of simple substances is constantly 
changing, as new discoveries are made. Those which 
rank under that term, at present, are fifty. 

5. Excepting the more general agents of nature, heat, 
light, and electricity, it is thought by some, that the sim* 
pie bodies may ultimately be resolved into metallic sub- 
stances, but this is doubted by others ; and no experi- 
ment on any one of the simple substances, tends to con- 
firm the hypothesis. 

6. The simple substances are at present divided into 
two classes ; the one called combustible or inflammable ; 
and the others, supporters of combustion, because in 
combining with the first class, much light and heat are 
developed. 

7. Should the experiments of the French chemists 
prove correct, with regard to some of the newly discov- 



TO CHEMISTRY. 11 

ered substances, the present division between the com- 
bustible bodies and those which support combustion, will 
hardly be warranted. 

8. Some of those which support combustion, appear 
to act the part of both, combustibles and supporters. 

Illustration, Sulphur gives light and heat to a certain 
extent, in its combination with some of the metals, and 
also when it combines with oxygen, with which as an in- 
flammable body it forms an acid. In the opposite char- 
acters, like chlorine and iodine, it forms an acid with 
hydrogen, which is termed the hydrosulphuric acid. 

9. Some suppose that phosphorus, carbon and azote, 
have a property similar to that of sulphur. 

10. Most of the simple combustibles have been prov- 
ed to be metals^ and hydrogen is believed by some to be 
a metal in an elastic form. 

1 1 . Those bodies whose metallic natures have not 
yet been fully ascertained, appear to possess the property 
of combining more strongly with inflammable bodies, 
than the metals with each other in forming alloys. 

12. The combinations of metals with those that are 
not metallic,are generally conspicuous and always definite. 

13. All the simple substances combine and form com- 
pounds, and from these, combined in different ways, an 
indefinite number of substances are produced. 

14. Chemical attraction, or the attraction of compo- 
sition, commonly called Chemical affinity, is a tendency 
which bodies of a different nature have to unite with one 
another, and form substances which are different from 
the bodies that have been combined. 

15. The attraction of aggregation is that which takes 
place between parts of the same substance, or between 
bodies of the same kind, and diifers not materially from 
the attraction of cohesion. 



12 INTRODUCTION 

16. An aggregate is a coherent body, and must be 
distinguished from a heap, for though a heap consists of 
parts all of a similar nature, yet those parts have no co- 
hesion with each other. 

Illustration. A mass of rock is an aggregate, where 
particles cohere, but a mass of sand is a heap, being com- 
posed of distinct and separate particles. 

17. A mixture is a mass of substances of a different 
nature. 

Illustration. Gunpowder composed of charcoal, sul- 
phur and nitre. 

18. There are several kinds of aggregation, as 1. 
The solid, as wood, metal, sulphur 2. The soft, as in 
glue, meat, jellies. 3. The liquid, as in water and oil. 
4. Aeriform, as in air and vapour. 

Illustration. Wax and tallow, when in a temperature 
of 50° are solid, at 80° soft, at 160° fluid, and between 
300 and 400° vapourized or aeriform. 

19. Every effort that tends to separate the particles 
of bodies, tends to destroy the attraction of aggregation. 
In all cases the force applied, must be more than equal 
to the force of attraction. 

Illustration. Grinding, cutting, pounding, &c. 

20. If the aggregation of a body be diminished, it ex- 
hibits a greater surface. 

Illustration. A lump of sugar or salt when broken into 
bits, will present a larger surface than when whole. 

Observation. By this means the energy of chemical 
agents is increased ; thus fluate of lime, (Derbyshire 
spar) is scarcely affected by sulphuric acid in the lump ; 
but let it be first ground into powder, and a rapid decom- 
position takes place ; the fluoric acid is disengaged in 
the form of gas, it being compounded of this acid and 
lime ; in the decomposition, the sulphuric acid combines 
with the lime, forming what is called sulphate of lime* 



TO CHEMISTRY. 13 

21. The force of this attraction is estimated by the 
power required to overcome it. 

Illustration. Hence arises the difficulty of cutting mar- 
ble, flint, and the diamond ; hence also the different de- 
grees of exertion required to separate the several kinds 
of timber. 

22. Different degrees of heat are required to over- 
come the several kinds of aggregation. 

23. Hot liquids not only dissolve substances quicker, 
but in much larger quantities ; when, however, the liquor 
cools, part of the substance falls to the bottom of the ves- 
sel, in regular crystals. 

Exp. Take an ounce of glaubers salt, sulphate of so- 
da, which has been dried over the fire and become a 
white powder, dissolve it in two ounces of boiling water; 
when cold, the original crystals will be seen in the fluid, 
notwithstanding the salt was reduced to powder. 

24. Chemical attraction differs from the attraction of 
aggregation in this ; the former unites bodies of different 
natures, while the latter only those of the same. 

Illustration. Sand and alkali exposed to a strong heat, 
combine and form a "substance called glass. In this state 
it is a uniform whole, which no mechanical efforts can 
again separate into sand and alkali, and the properties of 
glass are not only different from those of sand and salt, 
but in many respects quite contrary. It is transparent 
and insipid. 

Exp. 1 . Put a small quantity of mercury and sulphur 
into a crucible^ an ounce of each, and stir them together 
over a fire, till the sulphur is completely melted, then 
pour the mixture on a piece of glass or marble, previ- 
ously greased or warmed. The substance obtained from 
this composition, is sulphuret of mercury, and has neither 
colour, brilliancy, inflammability, nor volatility of eitfaei? 



14 INTRODUCTION 

©f its component parts. Neither can the ingredients be 
separated from each other by any mechanical means. 

2. Dissolve mercury in nitric acid, for which it has 
a strong affinity, to the point of saturation, that is, when 
it will dissolve no more, every particle of acid has at- 
tracted a particle of mercury. The liquid has lost its 
acid taste, and acquired that of a metallic one, if it be 
slowly evaporated, a salt will be formed, which in its 
properties and appearance is entirely different from its 
ingredients. 

3. The burning acid nature of quicklime and sulphu- 
ric acid is well known ; if we mix a small quantity of 
each together, the corrosive nature of both is destroyed, 
and the substance produced from this union is called 
Plaster of Paris, or gypmm ; in chemical language, it is 
sulphate of lime. 

4. A spoon-full of salt thrown into water and dissolv- 
ed, diffuses itself through the whole of the fluid, and the 
salt is said to be combined with the water; the water 
and the salt have a certain affinity for each other, they 
cannot be separated by any mechanical means ; but if 
another substance be added to which water has a great- 
er affinity than it has to the salt, it will quit the salt to 
unite with this third substance. If therefore alcohol be 
added, the water will leave the salt to join the spirit ; 
and the salt, by its superior gravity, will fall to the bot- 
tom of the vessel. 

5. Dissolve camphor in alcohol, the solution is per- 
fectly clear, which is another instance of chemical affini- 
ty. ; but the spirit has a stronger affinity for water than 
for camphor, and if a little of that be added, the camphor 
will foil down in white flakes, or in a solid form. 

6. Put some acetate of soda into a retort, add muriatic 
*icid and distil the mixture to dryness ; the fire will drive 



TO CHEMISTRY. 15 

off the acetic acid, but will have no effect on the muri- 
atic acid, while in combination with the soda, which 
proves that the soda has a greater affinity for the muri- 
atic acid than for the acetic. If now nitric acid be added 
to the muriate of soda, and heat applied, the muriatic 
acid will be driven off, the nitric acid is combined chem- 
ically with the soda, and the substance is a nitrate 
of soda ; to which, if sulphuric acid be added, and heat 
applied, the nitric acid will be expelled, and the sulphu- 
ric acid will unite with the soda, forming a true sulphate 
of soda. These changes take place in consequence of 
chemical affinity. 

25. Decomposition and division are very different in 
their operations ; the latter simply reduces a body into 
parts, while the former separates the various ingredients 
of which it is composed. 

Illustration. When we break with a hammer a piece 
of marble, we merely divide it, each part still retaining 
all its constituents, and this may be done without any 
knowledge of chemistry; but when the chemist attempts 
to analyze it, he finds it composed of carbonic acid and 
lime, for this purpose he applies a third substance which 
has a greater affinity for lime than the carbonic acid has,, 
by this means he separates the constituents, this is called 
decomposition. 

26. When we decompose a substance, we resolve it 
into its constituent parts ; when we divide it, into inte- 
grant parts ; hence the difference between elementary 
and integrant particles. 

27. Bodies are decomposed by chemical attraction, 
by adding a third substance which has a greater affinity 
for one of its constituents -than the other, in this way it 
unites with one, and the other is set at liberty. 



i 6 L\TR.ODUCTIOtf 

Illustration. This may be illustrated by three letters, 
A. B. C. Let the two ingredients be A and B ; present 
to this compound the third ingredient C. which has a 
greater affinity for B.. than that which unites A and B. it 
follows that B. will quit A. to unite with C. ; therefore 
C. has effected a decomposition of A. B. A. has been 
dismissed, and B. and C. form an union. 

Exp. Dissolve some nitrate of copper in water, and 
immerse in it a piece of clean bright iron. A decompo- 
sition takes place, the nitric acid having a stronger affin- 
ity for the iron than it has for the copper, attacks the 
iron and setting at liberty the copper, it is precipitated 
in its metallic form. 

28. Chemists have established certain principles cal- 
led Laws of affinity. The first is, that it acts only in the 
union of bodies of different natures, and forms a third 
substance totally different from either of the constitu- 
ents. 

Illustration* Sulphuric acid and soda when combined^ 
form glauber's salt, or sulphate of soda. 

Second. Chemical affinity acts only between the mi- 
aute particles of bodies. 

Exp. A lump of sulphur thrown into alcohol, will 
cause no action ; but if the sulphur be minutely divided^ 
the bodies will unite, and the solution be perfectly trans- 
parent. The union is thus effected ; put some pounded 
sulphur into a cucurbit A. Plate 2, fig. 2, suspend within 
it a phial B. containing alcohol ; and when the whole is 
covered with the head C. and the joinings well luted, 
heat the apparatus by means of the lamp F. The sul- 
phur will soon rise up in small particles, and will unite 
with the particles of alcohol which will likewise be driv- 
en off by the heat, and will be collected in the matrass X. 

To prove that the sulphur has united with the alcohol. 



TO CHEMISTRY. 



11 



add some distilled water for which the alcohol has a 
stronger affinity than for the sulphur, the latter will be 
precipitated. 

Third. Attraction may take place between several 
bodies ; thus two, three, or more metals may be fused 
together, so as to produce compounds, the properties of 
which are very different from those of the constituent 
parts. 

Exp. Melt eight parts of bismuth, five of lead, and 
three of tin together, and when united, the compound is 
so fusible, that a spoon made of it will melt in boiling- 
water. This property none of the metals possess sepa- 
rately. A composition of equal parts of lead, zinc and 
bismuth Is so fusible, that it may be kept in fusion on a 
paper held over the flame of a candle. 

Fourth. Bodies will not unite chemically, unless one 
of them, at least, be in a fluid or aeriform state. 

Illustration. Neither sugar nor salt will combine with 
ice ; but they both unite with water. 

Fifth. When two or more bodies unite by affinit; , 
their temperature suffers a change at the instant of union. 
Exp. 1. In a wine glass half filled with cold water, 
pour some sulphuric acid very gradually, a heat will be 
immediately perceived, which by the addition of the acid 
may be increased above that of boiling water. 

2. Hold in one hand a phial containing some pulver- 
ized muriate of ammonia, sal ammoniac, upon which pour 
cold water, and shake the mixture, a sensation of great 
cold will be immediately produced. 

Sixth. By chemical affinity some bodies acquire prop- 
erties very different from those which the compounding 
bodies had previously. 

Illustration. Iron and tin when combined by fusion, 
lose the property of malleability and ductility, 
2* 



18 



1NTR0DUCT I OX 



Exp. Drop concentrated sulphuric acid gradually into 
a saturated solution of muriate of lime, a solid will be 
formed from the two fluids. 

Scventlu The action of two compound substances, by 
which they mutually decompose each other, and produce 
two or more new substances, is called compound affinity. 

Exp. 1. If to a solution of sulphate of ammonia, there 
be poured nitric acid, no action takes place, because the 
sulphuric acid has a greater affinity for ammonia than 
nitric acid. But if instead of nitric acid, a solution of 
nitrate of potash be poured in, a double decomposition 
takes place, and by evaporation, two new bodies ara ob- 
tained, a sulphate of potash and nitrate of ammonia. In 
tliis case, the sulphuric acid of the sulphate leaves the 
ammonia to unite with the potash ; and the nitric acid is 
disengaged and unites with the ammonia. 

Exp. 2. If the sulphate of alumina be mixed with 
the acetate of leal in solution, a mutual decomposition 
takes place ; the acetic acid of the acetate unites with 
the alumina, and the sulphuric acid with the lead. 

29. The cause of chemical ainnity or attraction of 
composition has net been fully ascertained. 

Observation, In 1803, Berzelius and Hisinger disco v 
creJ the law respecting the agency of the galvanic bat- 
tery in the decomposition of bodies, viz. " That oxygen 
and acids are accumulated round the positive pole ; 
while hydrogen, alkalies, earths and metals, are accu- 
mulated round the negative pole." From this general 
law Berzelius deduced the conseqnence T that the decom- 
positions in such instances were owing to the attractions 
subsisting between the bodies and the respective elec- 
tricities. This opinion was extended by Sir H. Davy, 
with which Berzelius afterwards coincided. According 
4o these celebrated chemists, chemical afnnity is identi- 



TO CHEMISTRY 



19; 



cal with electrical attraction, and bodies which unite 
chemically, possess different kinds of electrical attractions. 
Every body, in their opinion, possesses a permanent elec- 
tric state, either resinous or vitreous. Two bodies in 
the same state of electricity have no affinity for each 
other, consequ9ntry,.the attraction of cohesion which takes 
place between substances of the same nature, cannot be 
the same as electric attraction. 

According to the above theory, bodies in opposite 
states have an affinity, and the strength of this affinity is 
in proportion to the degree of intensit}^ of the different 
electricities in the two bodies ; in order to make bodies 
separate from each other, we have only to bring them 
into the same electric state by making them both vitre- 
ous or both resinous. It remains for future discoveries 
to ascertain whether this hypothesis be founded in truth ; 
but there can be no question that electricity has great 
influence in the combination of bodies. 

We shall consider this subject further^ under the arti- 
cle, electricity and galvanism. 

PRACTICAL QUESTIONS. 
How are substances divided in chemistry 1 
What are simple bodies ? 
How did the ancients consider this subject ? 
How should the term elements be considered ? 
What are the number of simple substances ? 
Into what may the simple bodies be resolved ? 
Enumerate them. 

Into how many classes are these substances divided ? 
But may not this division be incorrect ? 
Do any substances act the part of combustibles and 
supporters ? - . . 

Illustrate this. 



20 INTRODUCTION 

What is thought of carbon, phosphorus and azote ? 

What is carbon and azote believed to be ? 

What has been proved with regard to the simple com- 
bustibles ? 

What do those bodies which have not been proved me- 
talic, appear to possess ? 

How is the combination of metalic with non-metalic 
substances ? 

How is the combination of simple substances ? 

What is chemical attraction ? 

What is the attraction of aggregation ? 

How does an aggregate differ from a heap ? 

Illustrate this. 

What is a mixture ? 

Illustrate it. 

How many kinds of aggregation are there ? 

Illustrate it. 

How is the attraction of aggregation destroyed ? 

If the aggregation of a body be diminished, what does 
k exhibit ? 

How do you illustrate this ? 

How do you estimate the force of this attraction ? 

What is required to overcome the different kinds of 
aggregation ? 

What effect have hot liquors to dissolve substances ? 

How does chemical attraction differ from aggrega- 
tion? 

Illustrate it. 

What is the difference between decomposition and di- 
vision ? 

Illustrate it. 

What do we, when we decompose a substance ? 
How are bodies decomposed ? 
Illustrate it. 



TO CHEMISTRY. 21 

What have been established by chemists with regard 
to attraction ? 

What is the first law T 

Illustrate it. 

W 7 hat is the second law t 

Illustrate it by experiment. 

What is the third law ? 

How would you illustrate it? 

What is the fourth Law ? 

Illustrate it.. 

What is the fifth law ? 

Illustrate it by experiment 

What is the sixth law ? 

Illustrate it. 

What is the seventh law ? 

Illustrate it by an experiment. 

What is the cause of chemical attraction ? 

What observations have you to make on, this subject I 



chap. m. 

Tfieory of Atoms, — Definite proportions — Chemical Equiv- 
alents, 4"C. 

1. The atomic theory is the manner of explaining 
the composition and decomposition of bodies by consid- 
ering their ultimate atoms or particles as peculiar and dis- 
tinct elementary solids, never changing in their figure, 
weight, or volume, and utterly incapable of being di- 
vided. 

2. By means of this theory which i3 now generally 
admitted under certain modifications, by the most scien- 



22 INTRODUCTION 

tific Chemists, Chemistry has been elevated to the rank 
of a mathematical science, and made to occupy one of 
the most distinguished places in the field of philosophical 
research. 

3. Sir Isaac Newton seems to have had an idea of the 
theory of atoms, or ultimate particles, by the following sen- 
tence. After speaking of the laws of chemical attraction, 
he proceeds as follows. "All these things being considered, 
it seems probable to me that God in the beginning formed 
matter in solid, massy, hard, impenetrable, immoveable 
particles, of such sizes and figures, and in such propor- 
tions to space, as most conduced to the end for which he 
formed them ; and these primitive particles being solids, 
are incomparably harder than any porous bodies com- 
pounded of them ; even so very hard as never to wear or 
break in pieces ; no ordinary power being able to divide 
what God himself made one in the first creation. While 
the particles continue entire, they may compose bodies of 
one and the same nature and texture in all ages ; but 
should they wear away, or break in pieces, the nature 
of things depending upon them would be changed. 
Water and earth composed of worn out particles, and 
fragments of particles would not be of the same nature 
and texture, now, with water composed of entire particles 
in the beginning. And therefore, that nature may be 
lasting, the changes of corporeal things are to be placed 
only in the various separations and new associations and 
motions of these permanent particles, compound bodies 
being apt to break, not in the midst of solid particles, but 
where those particles are laid together, and only touch 
in a few points." 

4. Mathematicians conceived matter to be infinitely 
divisible, but, in nature its divisibility was thought to be 
limited to the hard and impenetrable atoms. 



TO CHEMISTRY. to 

& The idea of atoms appears to hare been first pro- 
mulgated in any chemical work in 1790, by Mr Higgins, 
and by J. B. Richter, of Berlin, in 1 792. Very little notice 
was taken of the subject by chemists until Mr. John Dalton 
of Manchester j Eng. published his system of definite pro- 
portions, since which it has received additional support 
and improvements by the most celebrated chemists in 
different parts of Europe. 

6. The French chemists have adapted the atomic the- 
ory under another form, which agrees with the lan- 
guage given by Berzelms, viz that of volume. 

1, Dr. Wollaston introduced into the science, the term 
chemical equivalents, to express the different ratios in 
which the corpuscular subjects of this science reciprocal- 
ly combine, referred to a common standard which is 
reckoned unity. — Plate 1 . 

7. He assumed oxygen as a standard, from its being 
almost universally combined in chemical matter. 

8. If oxygen be made unity, we shall have in the fol- 
lowing table, their ratios reduced to their lowest terms 
in which the equivalents will be prime ratios or pro- 
portions. 

The lowest ratio, or equivalent prime of 
oxygen being 1,000 



That of hydrogen will be 0,126 

Offluor? 0,375 

Of carbon, - - . - - - 0,750 

Of phosphorus, - . . . 1,500 

Of azote, ...... 1,750 

Of Sulphur, - - - <- 2,000 

Of calcium, .... - 2,550 

Of sodium, 2,950 

Of potassium, .... - 4,950 

Of copper, 8,00 



24 INTRODUCTION 

Of barium, ... - 9^75 

Of lead, 13,00&c. 

9. The substances in the above table, susceptible of 
reciprocal saturation, can combine with oxygen, or with 
each other, not only in proportions corresponding with 
these numbers, but frequently in multiple or submultiple 
proportions, as in 1 and 1 : 1 and 2, &,c. from this have 
been adduced two general proportions of vast importance 
to the science — viz. 1st. The mutual action ofthe sat- 
urating porportions. — 2d, The multiple and submultiple 
proportions of prime equivalents in which any one body 
may unite with any other body to constitute successive 
binary compounds. 

10. The first of these laws was inferred from the re- 
markable and well established fact, that two neutral salts 
in decomposing each other, produce two new saline com- 
pounds perfectly neutral. 

Illustration. — Sulphate of soda being added to muriate 
of lime will produce perfectly neutral sulphate of lime 
and muriate of soda. 

1 1 . Richter drew the following conclusion. — 1st, That 
the quantity of two alkaline bases, sufficient to neutralize 
equal weights of any one acid, are proportionable to the 
quantities of the same bases sufficient to neutralize the 
same weights of every other acid. 

Illustration. — Six parts of potash or 6 of soda, will neu- 
tralize 5 of sulphuric acid, and 4.4 of potash will saturate 
5 of nitric acid. Therefore to find the quantity of soda 
equivalent to the saturation of this quantity of nitric acid, 
it may be computed by the proportional rule of Richter 
without having recourse to experiment, in the following 
manner, as 6 : 4.4 : : 4 : 2.93 : that is, as the potash equiv- 
alent to the sulphuric acid, is to the potash equivalent to 
the nitric acid, so is the soda equivalent to the first, to 
the soda equivalent to the second. 



TO CHLMISTEY. go 

2. G.5 potash, saturate 5 of muriatic acid gas, what pro- 
portion of socfc» by Richters rule, will be required to pro- 
duce the same effect ? We say 6 : 6.5 : : 4 : 4.3. 

3. If 10.9 potash combine with 5 of carbonic acid, 
how much will be equivalent to that effect. Now, 6. 
10.9 : : 4 : 7.26. Here we have found, that if 6 potash 
be equivalent to 4 soda, in saturating 5 of sulphuric acid, 
this ratio of 6 to 4, or 5 to 2, will pervade all the saline 
combinations ; so that whatever be the quantity of pot- 
ash requisite to saturate 5, 10, &c. of any other acid, two 
thirds of that quantity of soda will suffice. 

4. In the same manner let us find out for five of sul- 
phuric acid, or *of any one standard acid, the saturating 
quantity of ammonia, magnesia, lime, strontites, barytes, 
peroxide of copper, and the other bases; then their pro- 
portions to potash, thus ascertained, for this acid, will, hv 
arithmetical calculation, give their saturating quantity of 
every other acid, whose relation to potash, or any other 
of these bases is known. 

12. The verification of the above important law oc- 
cupied Richter from the year 1791, to 1802. With in- 
defatigable zeal he examined each acid in its relation to 
the bases, and then compared the results .with those o-iv- 
en by calculation, which he arranged in an extensive se- 
ries of tables. But all his tables have since been reduced 
into a single one, of 21 numbers, divided into two col- 
umns, by means of which, every question relating to the 
included articles might be solved by the rule of three, or 
a sliding scale. — Plate 1. 

The following table was composed from Richter's last 
tables. 

3 



26 



INTRODUCTION 



Bases. 




Oxygen 
=1. 


Acids. 


Ox'gen=l 


Alumina, 


525 


2.625 


fluoric, 


427 


7.135 


Magnesia, 


615 


3.075 


Carbonic, 


577 


2.885 


Ammonia, 


672 


3.36 


Sebacic, 


706 


3.530 


Lime, 


793 


3.965 


Muriatic, 


712 


3.560 


Soda, 


859 


4.245 


Oxalic, 


755 


3.775 


Strontian, 


1229 


6.645 


Phosphoric 


, 679 


4,895 


Potash, 


1605 


8.025 


Formic, 


983 


4.94 


Barytes, 


2222 


1.111 


Sulphuric, 


1000 


5.000 








Succinic, 


1209 


6.045 








Nitric, 


1405 


7.025 








Acetic, 


1480 


7.400 








Citric, 


1483 


8.415 








Tartarous, 


1694 


8.470 



The object of the above table was to give directly the 
quantities of acid and alkali requisite for mutual satura- 
tion. For example, 1605 opposite to potash is the quan- 
tity of that alkalic equivalent to neutralize 427 fluoric 
acid 527 carbonic, 712 muriatic, 100 sulphuric, kc. 
Each column affords also progressive increasing numbers, 
Those nearest the top have the greatest acid or alkaline 
energies as measured by thek powers of saturation. 
Hence the first columns, give, as far as analysis would jus- 
tify, in the time of Richter, a table of the relative weights 
of atoms. 

14. Two chemical constituents frequently unite ifi 
different proportions, forming distinct and often dissimilar 
compounds. 

Illustration. Oxygen and nitrog-en unite and constitute 
in one proportion nitrous oxide ; in a second proportion 
nitric oxide. In a third nitrous acid, and in a fourth 
nitric acid. The law by which these various compounds 
are regulated, is the doctrine of definite proportions. 

1 5. By this hw r^odips vtva svtwosed to 1 e crrrt^ssd 



TO CHEMISTRY. TC 

the different compounds. These atoms are supposed tc 
be spherical, and can only combine 1 atom to 1, 1 to 2, 1 
to 3, and so on. The number of the atoms of one ele- 
ment being some multiple to the atoms of the other. 

16. Hence it follows that bodies unite together in cer- 
tain definite proportions by weight, that certain weights 
of some bodies ccmbine with certain weights of other 
bodies. 

17. Substances in a gaseous state havejbeen demon- 
strated to combine with reference to their bulk or volume^ 
that is, one volume of one gas always combines with one 
or more similar volumes of another, and not with any odd 
fractional parts. The volume or bulk of the resulting 
compound, if it happens to be gas, always bears a similar 
relation to the original volumes of its component gases. 

18. The same weights of the same resulting com- 
pounds are formed when bodies unite in a gaseous state 
according to their volume, as when they unite in any oth- 
er manner according to their weight. 

Illustration. 1 volume, (say 100 cubic inches) of muri- 
atic gas will, unite with 1 volume, 100 cubic inches of am- 
moniacal gas, and form the same w r eight of the same com- 
pound, viz. muriate of ammonia, as if 39,183 grains, the 
absolute weight of 100 cubic inches, of muriatie acid, unit- 
ed with 18.003 grains ; the absolute weight of 100 cubic 
inches of ammonia ; the two numbers 39.183 and 18.003 
being to one another as 1.278 : 5900, or as 37 : 17. The 
specific gravities and the weights of these two substances 
respectively. 

19. If the hypothesis and data are correct, it follows 
that the weights of the atoms of bodies are to one anoth- 
er as the specific gravities of the same bodies in a state 
of gas. 

20. If hydrogen be taken as unity, as is the case in 



2£ INTRODUCTION 

DaltoiTs experiments, then the weights ©f the atoms ef 
all bodies will be multiples of this unit ; this is verified 
partly by experiment, and partly by hypothesis* 

21. The above opinion has been formed upon the fol- 
lowing grounds. — 1st, The specific gravity of ammc- 
niacal gas, according to Sir fit. Davy, is 590164, common 
air being 1,000. According to Riot and Arrago it is a trac- 
tion greater ; hence Dr. Prout infers it to be 5902 as the 
specific gravity of this gas,. The specific gravity of ni- 
trogen, he assumes as 9T22, common air being 1,000. 
JSTow as ammonia is known lobe composed of one volume 
nitrogen and three volumes hydroger, condensed into two 
volumes, the specific gravity cfc* hj Jrcgcn. according, to 
these data must be 0694. 

22. Atmospheric air is admitted to be universally 
composed of about 21 per cent of oxygen, and 79 per cent 
of nitrogen, which so nearly corresponds with one voluma 
of oxygen r and four volumes of nitrogen, or 20 of the 
former to 80 of the latter, that it is inferred to be its true 
composition. Now the weight of the atom of oxygen 
being supposed to be so, and that of the atom nitrogen 
17.5 the specific gravity of oxygen gas, accordingly, will 
be Kllll and that of nitrogen 9722. These numbers 
are multiples of 0694, for 1.1111, divided by 0694=10 
and 9722 divided by 0694=14... 

23. There are some substances whose specific grav- 
ities do not correspond with the weight of their atoms. 
Thus the specific gravity of oxygen is 16 times that of 
hydrogen, while the weight of its atom, or its combining 
weight is only half or eight times that of hydrogen, but 
iae specific gravities are always some multiples of the 
weight of the atom. 

24. When the specific gravity is double the weight 
of the atom, as that of oxygen, we must suppose that the 



TO CHEMISTRY. 29 

particles are nearer each other in the proportion of 2 to 
1, or that two particles come together, and are surround- 
ed by the caloric which belongs to one of them in their 
single state. 

25. It appears that the oxygen puts on this single state 
of existence in the formation of carbonic oxide, because 
that gaseous body contains only 1 atom of oxygen ; hence 
its specific gravity is the same as if formed from a gas- 
eous oxygen of half the real specific gravity united to an at- 
om of carbon without any change of volume, the same as 
takes place when sulphur or carbon is burnt in oxygen 
gas. Hence the great tendency which oxygen possesses of 
combining in double doses with bodies, as is the case with 
carbon, sulphur, phosphorus, iron and many others, 

26. We have also an instance of a compound gaseous 
body becoming double the specific gravity which would 
be expected, in olefiant gas, which is composed of 1 atom 
carbon and 1 atom hydrogen. The specific gravity, 
hydrogen being 1, ought to be 1X5.4=6.4: whereas, in 
fact, it is about double of this. Hence we should con- 
clude that the repulsion between the particles is halved, 
or that the compound atoms have united in pairs by 
which the density is doubled. 

27. The quantity of acid, according to Gay Lussac, 
which the different metallic oxides require for saturation, 
is in direct ratio to the quantity of oxygen which they res- 
pectively contain. This principle was discovered hy 
observing the mutual precipitation of the metals, from 
their solution in acids. 

Experiment. 1. When we precipitate a solution of a- 
cetate of lead by a plate of zinc, a beautiful vegetation 
is formed, known under the name of the tree of Saturn 
and which arises from the reduction of the lead by a 
galvanic process. At the same time we obtain a solution 
3* 



3V ISTH0DUCTIO:f 

of acetate of zinc equally neutral with that of the lead, 
and entirely exempt from it. Very little if any hydrogen 
m disengaged during the precipitation, which proves that 
the whole quantity of oxygen necessary for the solution of 
the zinc and saturation of the acid, has been furnished to 
it by the lead,- 

2. If we put into a solution of sulphate of copper, 
slightly acidulous, bright iron turnings in excess, the cop- 
per is almost instantly precipitated ; the temperature ris- 
es and no gas is disengaged. The sulphate of iron which 
we obtain- is that in which the oxide is at a minimum, and. 
the acidity is exactly the same as that of the sulphate of 
copper employed. 

3. Similar results may be obtained by decomposing: 
the acetate of copper by lead, particularly by the aid of 
heat. But since the zinc precipitates the lead from its 
acetic solution,- we may conclude that it would also pre- 
cipitate copper, from its combination with acetic acid. 

4. Copper precipitates with facility silver, from its 
nitric solution. All the oxygen necessary for its solution 
is furnished to it by the oxide of silver, for no gas is dis- 
engaged,, and the acidity is not changed. 

5. The same thing happens with copper in regard to 
nitrate of mercury ; and to cobalt with respect to silver. 
Ja these examples, as well as the preceeding, the precip- 
itating metal is furnished with all the requisite oxygen 
from tl e metal, while it precipitates, all that is necessary 
for its oxidizement and for neutralizing to the same degree 
the acid of the solution. 

23. M.. Gay Lussac has shewn with regard to the same 
metals, at their different states of oxidizement, that they 
require of acid a quantity precisely proportional to the 
quantity of oxygen they may contain, or that the acids in 
the salts are exactly proportional to the oxygen in the ox- 



TO CHEMISTRY, 3i 

ides. This law affords a ready way of determining the 
proportions of all the metallic salts. The proportions of 
one metallic salt, and the oxidation of the metals being 
o-iven, we may determine those of all the salts of the same 
sjenus, or. the proportions of acid and of oxide of all the 
metallic salts ; and the oxidation of a single metal being 
given, we can calculate the oxidation of all the rest 7 
since the peroxides require the most acid v we can easily 
understand how the salts containing them should, in gen- 
eral, be more soluble than those with the protoxide. 

29.- Berzelius, a Swedish chemist, contributed es- 
sentially to the science of , chemical ratios. He assumed 
oxygen as the unit of proportion. 

30. Dr. Wollaston's scale of chemical equivalents, Plate 
1 , fig.l , has contributed more to facilitate the general study 
and practice of chemistry, than any other invention. 

31. Dr.-Wollaston discovered a series of numbers de- 
noting the relative primary proportions or weights of the 
atoms of the principal chemical bodies, both simple and 
compound. These were determined from a general view 
of the most exact analysis of other chemists as well as 
his own. 

32. The list of substances which Dr. Wollaston has 
estimated, are arranged on one or other side of a scale of 
numbers, in the order of their relative weights, and at 
such distances from each other, according to their weights, 
that a series of numbers placed on a sliding scale, can at 
pleasure be moved, so that any number expressing the 
weight of a compound, may be brought to correspond 
with the weight of that compound in the adjacent column. 
The arrangement is such, that the weight of any ingre- 
dient in its composition, of any reagent to be employed, 
or precipitate that might be obtained in its analysis, may 
be found opposite the point at which the respective 
name is placed. 



3£ INTRODUCTION 

33. If the slider be drawn upwards until it corres- 
ponds with the muriate of soda, the scale will then show 

'iiow much of each substance contained in the table is 
equivalent to two of common salts ; viz. 26,8 dry muriatic 
acid, and 53.4 of soda, or 39.8 sodium, and 13.6 oxygen ; 
or if viewed as chloride of sodium it contains 60.2, chlo- 
rine, and 39,8 sodium. With respect to seagents, it may 
be seen that 389 nitrate of lead containing 191 of litharge 
employed to separate the muriatic acid, would yield a 
precipitate of 237 muriate of lead, and that there would 
then remain in solution nearly 146 of nitrate of soda. It 
may at the same time be seen that the acid in this quan- 
tity of salt, would serve to make 232 eorrosive sub limate, 
containing 185.5 red oxide of mercury, or make 91.5 
muriatic of ammonia, composed of 62 muriatic gas, and 
29.5 ammonia. 

34. The scale shews also that for the purpose of ob- 
taining the whole of the acid in distillation, the quantity 
of sulphuric acid required is nearly 84, .and that the res- 
idum of this distillation would be 122 dry sulphate of 
soda, from which might be obtained by crystallization, 
277 glauber's salts containing 153 water of chrystalliza- 
tion. 

Observation. — -These and many other similar examples 
may be performed by motion of the slider, either up or 
down, so as to correspond with its place in the adjacent 
column, which must be of incalculable advantage to the op- 
erative chemist. 

35. When we wish to reduce analytical results, as 
usually given for two parts, to the equivalent prime ratios^ 
or in other words to the atomic proportions, we must pro- 
ceed on the following principles. 

1. As in all reasoning, we must proceed from what is 
known or determinate, to what is unknown or indeter- 



TO CHEMISTRY.. 3£> 

minate, so in every analysis, there must be one ingredi- 
ent whose prime equivalent is well ascertained. This is 
compared as the common measure, and the proportions 
of the rest are compared to it. 

Take fluate of lime to determine the unknown number 
that should denote the prime of fluoric acid. 

In the first place 2 primes oxygen =2, combine with 
i of cartxxbssO.tfSj to form the compound prime 2.75 
carbonic acid. We likewise know that carbonate of lime 
consists of 43.6 carbonic acidx 54,4 lime. We therefore 
make this proportion to determine the prime equivalent 
of lime 

43.6 : 54.4 : : 2.75 : 356= prime of lime. 

2. It has heen ascertained that 100 parts of dry sulphate 
of lime, consists of 41.6 lime^and 58.4 acid. Hence to 
find the prime of sulphuric acid, we make this propor- 
tion. 

41.6 : 58.4 : : 3.565 :=prime of sulphuric acid. 

There has been obtained from 100 of fluor spar or flu- 
ate of lime in powder, acted on by sulphuric acid, and ig- 
nited 175.2 grains of sulphate of lime. Now since 100 
grains of sulphate of lime contain as above 41.6 of lime 
we have this proportion. 

100: 41.6:: 175.2 : 72.88 =lime corresponding to 175.2 
grains of sulphate, and previously existing in the 100 grs. 
of fluor spar. If from 100 we substract 72.88, the differ- 
ence 27.12 is the fluoric acid, or the other ingredient of 
the fluor, which saturated the lime. Now to find its 
prime equivalent, we say, 

72.83: 356 : : 27.12 : 1.325=the atom of fluoric acid. 

Observation — According to Dr. Thomson, the number 
3.625 represents the atom of lime, consequently the atom 
of fluoric acid would be. 1,3015. 

36.. M. Vauquelin found that 33 parts of lime saturat- 



bi INTROrUCTlG.t 

ed with sorbic acid, and carefully dried, weighed 100 grs. 
Hence the difference, 67 grains, was acid. To find its 
equivalent prime, we say 

33 : 6-7 : : 3.55 == the prime of lime : 7.23 the 
prime of the acid. But as he brought it to absolute neu- 
trality by a small portion of potash, we may, according to 
Dr. Ure, take 7.5 for the acid. 

37. M. Vauquelin subjected the acid, as-it exists in 
the dry sorbates of lead and copper, to an analysis by fire, 
and obtained the following results : 

Hydrogen, 16.8 

Carbon, 28.3 

Oxygen, 54.9 

100.0 
Now such an assemblage of the primes or atoms of 
these elements, must be found as will form a sum total of 
7.5 ; and at the same time be to each other, in the above 
proportions. The following rule is given for the solu- 
tion, and by a sliding rule it may be found by inspec- 
tion. 

Multiply each proportion per cent, by the compound 
prime, and compare the products hj the multiples of the 
constituent primes. The number of each prime requis- 
ite to compose the whole, can then be estimated thus, 

Theory. Experiment. 

0.168X7.5=1.2600 or 10 hydrogen =1.25 16.7 16.8 

0,283X7.5=2.1225 3 Carbon =2.25 30.0 2.8.3 

0.549X7.5^=4.1175 4 Oxygen =4.00 53.3 54.9 



7.50 100.0 100.0 

If on Dr. Wollaston's scale, we mark with a pencil 2h, 
3h, and up to lOh ; 2c, 3c, 4c, 5c ; and 2n, 3n, 4n ; respec- 



TO CHEMISTRY. 35 

lively opposite to twice, thrice, &c. the atoms of hydrogen, 
carbon and nitrogen, we shall have ready approximations 
to the prime components, by inspection of the scale. 
Move the sliding part, so that one of the quantities per 
cent, may stand opposite the nearest estimate of a mul- 
tiple prune of that constituent. Thus we know that hy* 
drogen, carbon and oxygen bear relation to each other of 
4, 6, 8 ; of course the latter two that of 3 to 4. But 54.9 
oxygen being more than one half of 100, the weight of 
oxygen in the compound prime is more than the half of 
7.5, and therefore points to 4. Place 54.9 opposite 4 
oxygen, we shall find 13 opposite 10 hydrogen, and 30.7 
opposite 3 carbon. Here we see that the proportions of 
carbon and hydroygen are both greater than by Vauquil- 
in's analysis. Try 51 opposite 4 oxygen, then opposite 
3 carbon, we have 28.7, and opposite 10 hydrogen 16.9. 

39. If the weight of the compound prime is not giv- 
en, then we must proceed to estimate the nearest prime 
proportions, after inspection of those per cent. 

40. Chemists differ with regard to their equivalent 
numbers. There are three systems at present used in 
England; 1st, That having oxygen as the root; 2nd, 
That having one volume of hydrogen as the root ; 3d 
That having two volumes of hydrogen as the root, on the 
hypothesis of Dalton, that two volumes of hydrogen con- 
tain the same number of atoms, as one volume of oxygen, 
but this supposition wants proof. 

Since the volume of hydrogen is equal in weight to 
1.6th the weight" of the volume of oxygen, the two first 
systems are mutually convertible by multiplying the 
number for oxygen, in the oxygen ratio, by 16, or 4X4 
to obtain the number in the hydrogen scale, and inverse- 
ly, it may be re-converted, or by dividing by 16, or 
br 1>' 1. 



36 INTRODUCTION 

41. Dr. WoIIastoivs scale, and Sir H. Davy's propor- 
tional number? are adapted to the idea that water is a 
compound of 1 hydrogen* 7.5 oxygen by weight, or 1 5X 1 
by volume. Their mutual conversion is therefore very 
easy, for by adding to Dr. Wotfaston's number its half, 
the sum is Sir H. Davy's ; consequently, if 'we subtract 
from the number of the latter, its third, the remainder is 
Dr. Woilastoivs number, 

■PR ACTIO AL QUESTIONS. 

What is called the atomic theory ? 
What has this theory done for chemistry? 
What was Sir I. Newton's opinion of atomsi 
How is divisibiity thought to be limited f 
When, and by whom was the atomic' theory first pro- 
mulgated ? 

Have the French chemists adapted the atomic theory ^ 
What did Dr. Wollaston introduce into chemistry ? 
What does he assume ns a standard ? 
What two important propositions have been addu- 
ced ? 

From what was the first of these laws inferred ? 
How do you illustrate this ? 
What conclusions did Richter draw ? 
Illustrate it. 
How long was Richter occupied in verifying this law ? 
Do the chemical constituents ^ver unite in different 
proportions ? 
Illustrate it. 

How are bodies supposed to be composed by this law ? 
What follows from this ? 

W r hat is formed when bodies unite in a gaseous state, 
according to their volume; 
Illustrate it. 



TO CHEMISTRY". 37 

If this hypothesis and data be correct, what fol- 
lows ? 

If hydrogen be taken as unity what follows ? 

Illustrate this by atmospheric air. 

Are there any substances w T hose specific gravities do 
not correspond with the weights of their atoms ? 

What must we suppose when the specific quantity is 
double the weight of the atoms, as that of oxygen ? 

When does it appear that oxygen puts on this single 
state ? 

What instance have we of a compound gaseous body 
becoming of double the specific gravity? 

What is the quantity of acid which the different metal- 
ic oxides require for saturation according to M. Gay 
Lussac ? 

Illustrate this by experiment. 

What has M. Gay Lussac shewn with regard to the 
same metal ? 

What does Berzelius assume as the unit of proportion ? 

Has Dr. Wollas ton's scale been of any advantage to 
chemistry ? 

How did Dr. Wollaston proceed ? 

Give a description of this scale. 

Illustrate the utility of the scale by an example. 

What does the scale shew with regard to distillation ? 

In what manner do you proceed when you wish to re- 
duce analytical results to equivalent prime ratios ? 

What is the complex problem of Vauquelin ? 

And what rule is given for its solution ? 
How would you proceed on Dr. Wollaston's scale ? 
Suppose the weight of the compound prime is not giv- 
en, how would you proceed ? 

Have all chemists adapted the same equivalent num- 
bers ? 

4 



33 INTRODUCTION 

How will you adapt the same scale to the two first 
systems ? 

To what idea is Dr. Wollaston's scale and Sir H. Da- 
vy's proportional numbers adapted ? 



CHAP. IV. 

Of Light. — Caloric. 

1 . We know little of light but by its effects. It is consider- 
ed by most philosophers as a material substance, immedi- 
ately emanating from the sun and from all luminous bodies, 
with inconceivable velocity,in right lines, in all directions. 

2. Some have considered light as vibrations propa- 
gated through an elastic medium which is diffused 
through all space, and in which luminous bodies have 
the power of exciting those vibrations, in the same man- 
ner that sonorous ones produce vibratory motions in the 
air. 

3. It best comports w r ith our ideas of its effects, to 
suppose light composed of certain particles of matter. 

4. " On the supposition that it be matter, its particles 
must be inconceivably minute, and endowed w r ith mutual 
and highly repulsive energies." 

5. The velocity of light is equal to 195,000 miles in 
a second of time. 

6. A ray of light projected from the sun is about ^ight 
minutes in passing from that luminary across the semi- 
diameter of the earth's orbit, or a space equal to 
95,000,000 of miles. 

Observation. The fixed stars are at least 400,000 times 
farther from us than the sun ; and it has been calculated 



TO CHEMISTRY. 39 

that a ray of light emitted from one of those luminaries, 
would be nearly six years in reaching us, so that if one 
of those stars were struck out of existence at this mo- 
ment, we should still continue to see it for that space of 
time to come. 

7. The momentum of the particles of light are unap- 
nreciable, for if they amounted to T ^ c of a grain, the 
force which they must necessarily acquire in moving 
through so vast a space, would be superior to that of a 
ball, discharged from a musket with a velocity equal to 
1700 feet in a second of time, and sufficient to reduce to 
powder any obstacle upon which they impinged. 

8, . It has been calculated that the momentum of light 
is -equal to that of a ball of iron, one quarter of an inch 
in diameter, moving at the rate of one inch in many mil- 
lions of millions of Egyptian years ! 

9. Such must be the minuteness of the particles, that 
if, according to Mr. Bowditch, they were placed in a row 
so as to form a line one inch in length, and a person at 
the creation had commenced counting them, at the rate 
of 120 in a minute, he would have enumerated at the 
present time a sufficient number to have constituted only 
a 300,000th part of an inch ! 

9. Light is not homogeneous, it is composed of differ- 
ent coloured rays, possessing different refrangibility. — 
The prismatic colours have been divided into seven, viz. 
red, orange, yellow, green, blue, indigo and violet. Red 
is the least, and violet the most refrangible. 

10. The rays of light must be extremely rare, for 
they cross each other in all possible directions, without 
the least apparent disturbance. 

Illustration. A variety of objects may be seen at the 
same time through a small pin hole in apiece of paper, 
Now the light, proceeding from these objects- m\M P&«? 



40 INTRODUCTION 

at the same instant through the hole in a great variety 
of directions, before they arrive at the eye ; yet the vi- 
sion is not in the least disturbed by it. 

11. The rays differ from each other in their illumi- 
nating power. Dr. Herschel found that the most intense 
light existed in the middle of the spectrum of green ray, 
and diminished towards each extremity. 

12. The violet rays possess the power of imparting 
the magnetic property to steeL 

Exp. Intercept all the rays except the violet, and 
having collected them into a focus by a lens, throw it on 
a needle, and carry it towards the extremity. This is 
to be repeated several times, and always towards the 
same extremity ; after some time the needle acquires 
polarity. 

13. Light is considered as constituting an important 
part of all inflammable substances. In every instance of 
combustion, light is disengaged, and is thought to depend 
on the combustible body. 

Illustration. Examples have been adduced to prove 
that light depends on the combustible body. The colour 
of the light emitted is peculiar to the body burned, this 
would scarcely happen unless the light depended on it ; 
as the oxide of copper exhibits a green light ; indigo- 
gene, a blue ; hydrogen, a greenish blue ; sulphur, a 
pale blue ; phosphorous, a white, &c. 

14. Bodies which possess the property of emitting 
light, either spontaneously or by combustion, so as net to 
decompose them, are called phosphorescent 

Illustration. Many chemical compounds possess this 
property in an eminent degree. In some cases it is ex- 
cited by heat, or by the solar ray ; in others, spontane- 
ously, as in dead animals and vegetable substances ; in 



TO CHEMISTRY". 41 

the latter, it probably owes this property to incipient 
decomposition. 

Exp. Put half an ounce of herring or mackerel into 
a phial capable of holding" four ounces, with two ounces 
of water, holding in solution half a drachm of common 
salt ; place the phial in a dark place, and in two or three 
days, a ring of light will appear on the surface of the il- 
quid, and by agitation, the whole liquid becomes lumi- 
nous, and continues in that state for some time. A mod- 
erate heat increases the luminous quality, but a boiling 
one destroys it. 

15. The light emitted from animal and vegetable 
substances in a state of decomposition produces no effect 
on the most delicate thermometer ; hence, it is inferred, 
that light constitutes a component part of these substan- 
ces, and that it is the first which is extricated, when the 
substance containing it, is beginning to be decomposed ; 
or when the putrefactive fermentation commences. 

16. Some living animals possess the phosphorescent 
power in different parts of their bodies. 

Illustration, The glow worm and fire fly. 

17. The chemical agency of light is very striking ia 
many of its effects. The beauty of colour and fragrance 
of vegetables, appear to depend on it entirely; and it 
has even an influence on their health and vigour. 

Illustration 1. If light be excluded from a growing 
vegetable for any length of time, it shoots out rapidly at 
first, seeming in quest of its great supporter ; but if de- 
nied it, it turns pale, sickens and dies. 

2. It is a well known fact, that plants kept in pots in 
houses, will, in a short time, turn their heads to that quar- 
ter whence the light proceeds ; if they are turned round, 
or their position be changed, they will immediately be- 
gin to return to their former situation j and if the light- 
4* 



42 INTRODUCTION 

proceed only from above, they will shoot up perpendicu> 
larly. 

18. Plants which grow in the shade, lose in a great 
measure their inflammable power ; hence, light seems 
necessary to the very existence of combustible bodies. 

19. Light appears to have an influence on the colour 
of animals, as well as vegetables. 

Illustration. That part of fish which is exposed to the 
action of the sun's rays, becomes black, or of a dark col- 
our, while the lower part is white. The plumage of 
birds is much more beautiful and variegated, in those 
parts of the world where the sun's rays are the most 
powerful. Thus birds possessing the most variegated 
and vivid colours, are found within the tropics. The 
hair of animals, living in high latitudes, turns white dur- 
ing winter. 

20. The solar rays have been divided into three dif- 
ferent kinds. 1. Colorific, or those producing colour. — 
2. Calorific, or the those producing heat. 3. Deoxydiz- 
ing, expelling oxygen, and restoring the oxides of metals 
to their metalic state. 

21. The intensity of the calorific rays increases as 
their refrangibility decreases. The deoxydizing increase 
with their refrangibility. 

22. Almost all bodies have the property of absorbing 
the rays of light, but only a few emit it again. They 
do not, however, absorb all rays indiscriminately ; some 
absorb one coloured ray ; others, another, while they 
reflect the rest ; which is the cause of the different col- 
ours of bodies. What is called a green body, depends 
for its colour on the reflection of the green rays of light; 
red bodies reflect the red rays, while they absorb the 
others, and so of the rest. Hence the inference, that 
the different colours of bodies depend upon the affinity 



TO CHEMISTRY. 43 

of each for some particular ray, and its want of affinitj 
for the others. 

23. The different sources from which light is emitted 
in a visible form, are 1 . The sun and fixed stars. 2. Com- 
bustion, which is the act of combination of the combusti- 
ble with oxygen ; of course, the light emitted must have 
existed previously combined with the combustible or 
with oxygen. 3. Heat, when the body becomes lumi- 
nous by being heated in the fire, it is said to be red hot ; 
and it is found that all bodies that are capable of endur- 
ing the requisite degree of heat, without decomposition 
or volatilization, begin to emit light at the same tem- 
perature. 

Illustration. Iron is just visible in the dark : when 
heated to 635° of Farenheit ; it shines strongly in the 
dark, at 752° ; it is luminous in the twilight, just after 
sunset, when heated to 884° ; and it shines even in broad 
day light, if its temperature be about 1000°. 

24. Percussion, or the striking together of two bodies, 
is another source of light. 

Illustration. When flint and steel are struck together, 
light is produced, which is capable of inflaming tinder, 
gunpowder, &c. The spark is a small particle of the 
iron, which takes fire during its passage through the air* 
This is an instance of combustion. But light is emitted 
when two quartz stones are smartly struck against each 
other, though the substances are clearly incombustible* 

OF CALORIC. 

25. What is denominated heat is a sensation produ- 
ced by a substance called caloric, which penetrates all 
bodies, diminishes the attraction of their several parts, 
and uniformly expands their dimensions. 

£6. By means of this powerful agent, solid metals are 



44 INTRODUCTION 

fused ; liquids ratified ; and almost all substances in na- 
ture are converted into elastic, compressible, or aeriform 
fluids. - 

Observation. It has been asserted by Lavoisier, that 
all bodies of whatever kind, may exist in three different 
states, .solid,, fluid and aeriform. 

27. Caloric is found to exist under a variety of forms 
or modifications* „ It is said to be Free or radiant, and is 
commonly called heat or temperature ; it is that heat 
which is perceptible to our senses, and effects the 
thermometer, whatever may be its degree, or the source 
whence it is derived. 

28. Combined caloric is that which does not effect" 
the thermometer, and is not perceptible by our senses ; 
it is retained in bodies, by the force of affinity or attract 
tion, and becomes. a part of their substance. , 

29. Heat differs from caloric in this ; one is the causer 
the other, the effect The latter means that which pror 
duces heat ; while the former is merely the sensation. 

30. Liquids are combinations of solids with a larger 
portion of caloric than they naturally contain. 

Illustration* " Though caloric be the cause of liquidi* 
ty and the gaseous state, still bodies in a concrete form 
contain much of this matter combined. This is known 
by such processes as lower the temperature of different 
bodies. So long as any substance can, be cooled, so long 
it has the power of parting with heat ; and we have yet 
to learn the point at which we could assert that it has 
parted with all it contains." 

31. When caloric is added to water, it becomes va-. 
pour ; and when abstracted from it, it becomes ice. . 

Illustration. In the case of vapour, the caloric forces 
itself between the particles of the water, and causes 



TO CHEMISTRY. 45 

them to separate at such a distance, that the force of 
aggregation is destroyed. 

32. Bodies which exhibit properties arising from in- 
crease or diminution of caloric, are said to be of certain 
temperature. 

33. No substance has had its temperature reduced to 
0, in the scale of heat ; hence it may be inferred, that the 
particles of solid bodies are never in actual contract. 

34. Instruments for measuring the relative degrees 
of heat, are called Pyrometers and Thermometers, with 
suitable scales attached, indicating the degrees. 

35. The states in which bodies exist, admit of differ- 
ent degrees of density or consistence, arising for the 
most part, from the different degrees of caloric which 
they contain. Solids are of different degrees of density 
from that of gold to that of jelly. Liquids from the con- 
sistence of melted glue, or melted metals to that of 
ether. The different elastic fluids are susceptible of 
different degrees of density. 

36. Bodies admit of different degrees of consistence 
without changing their state, merely by the agency of 
caloric. 

Illustration 1. The expansion of solids is exhibited by 
the Pyrometer, which, in principle, is a bar of iron 
made to fit exactly when cold between two points, and 
the diameter such as barely tcr allow it to pass through 
an iron ring ; when heated, it will become sensibly long- 
er, and it will then be found incapable of passing through 
the ring. 

2. Copper is more expansible than iron ; and iron 
than platinum. 

37. Fluids are much more susceptible of dilatation 
than solids. 

Illusiraiioiu This fact is shewn by the expansion and 



46 INTRODUCTION 

contraction of mercury or spirit in a thermometer, or by 
immersing in water a glass ball with a long neck, and 
filled to a certain point with any coloured fluid. 

38. The degree of expansion produced in different 
liquids, varies considerably. 

Illustration. Water is more expansible than mercury, 
and alcohol than water. 

Exp. 1. Provide two glass tubes, terminated at one 
end with large bulbs ; fill the bulbs, the one with alco- 
hol, the other with water, and let the liquids be coloured, 
in order the better to observe the effect. Hold the bulbs 
in each hand, for a few moments, you will find the alco- 
hol dilates with the warmth of the hand, while the water 
remains stationary. 

2. Plunge the bulbs into a vessel containing hot wa- 
ter, and you see both liquids rise in the tubes, though the 
alcohol rises much higher than the water, which shews 
that the former is much more susceptible of dilatation. 

Observation. Thermometers are constructed on the 
same principle. 

39. A thermometer consists of a tube with a bulb. — 
Plate 2, fig. 3 A. the glass bulb. B. the tube. C. the 
scale attached to the tube. D. the liquid in the tube. — 
The degree which indicates the boiling point, simply 
means, that when the fluid is sufficiently dilated to rise 
to this point, the heat is. such, that water exposed to the 
same temperature will boil ; which, as the scale called 
Farenheit's, is. at 212°. When the fluid is so much con- 
densed as to sink to the freezing point, it indicates that 
water begins to freeze when exposed to that tempera- 
ture. 

40. Thermometers are constructed in the following 
manner. A glass tube of a capillary bore is procured^ 
having a small bulb at one end, wbich, together with 



PXlATE k. 



themmometer 




TO CHEMISTRY. 4^ 

part of the tube, is filled with purified mercury, which 
when introduced into the tube is boiled to expel the air 
or moisture that might be attached to it, and at the mo- 
ment it is in ebullition, the extremity of the tube, being 
drawn to a point by means of a blow pipe, is hermeti- 
cally sealed, to prevent any air from entering the tube. 
Or if the scale is to be graduated only to 212°, the ball 
is plunged into boiling water, and the point to which the 
mercury ascends accurately marked. For the purpose 
of graduating the scale, the thermometer is plunged into 
melting ice, and the place where the mercury stands 
marked. From the freezing to the boiling point on 
Farenheifs scale, is 180°, or equal parts ; and similar 
parts are taken above and below, for extending the 
scale. 

Observation, Farenheit's thermometer is the one com- 
monly used in this country and Great Britain. The space 
between the freezing and boiling points is divided into 
180°; but the scale begins at that point of temperature 
which is produced by a mixture of pounded ice and mu- 
riate of ammonia, or muriate of soda, which is 32° lower, 
making the whole distance 212°. 

41. The centigrade thermometer is divided into one 
hundred degrees, between the freezing and boiling points. 
The freezing point is marked 0, and the boiling 100°, 

42. In Reaumur's thermometer, the space between 
the freezing and boiling points is divided into eighty de- 
grees. The freezing point is marked 0, the boiling 80°, 

43. The Russian thermometer commonly r called De 
Lisle's, begins its graduation at the boiling point and in- 
creases towards the freezing, The boiling point ls^nark- 
ed 0, the freezing 150. 

Other fluids besides mercury, are sometimes used, such 
as linseed oil and alcohol \ the latter is used particularly 



48 INTRODUCTION 

for measuring low degrees of temperature, where mer- 
cury would become solid. 

For nice chemical experiments, an air thermometer 
is sometimes used. The bulb of air thermometers is 
filled with common air only, and its expansion or contrac- 
tion is indicated hj a small drop of any coloured liquor, 
which is suspended within the tube, and moves up and 
down according as the air within the bulb or tube expands 
and contracts. 

Observation. — In general, air thermometers however 
sensible to the changes of temperature, are by no means 
accurate in their indications. 

44. The air thermometer of Mr. Leslie, is of a pecu- 
liar construction : it is in the form of a double thermom- 
eter inverted, (Plate 2, fig. 4,) the tube is bent at right 
angles, placed on a stand, (C.) and has a large bulb at 
each end, (A. B.) filled with air, the liquor, which is sul- 
phuric acid coloured, is confined to a portion of the tube, 
and indicates, by its motion, the comparitive dilatation or 
contraction of the air within the bulb which points out 
the relative temperature. 

Exp. Heat the bulb (A) with the hand, the fluid will 
rise toward the bulb (B) and vice versa. 

If both bulbs be placed in the same temperature, the 
coloured liquor suffers an equal pressure on each side, 
and no change is effected. 

45. This thermometer cannot indicate the tempera- 
ture of any particular body, or of the medium in which 
it is immersed. Its use is to point out the difference of 
temperature between the two bulbs, when placed under 
different circumstances. It has therefore obtained the 
name of u Differential thermometer." 

46. When the temperature of a body is above the 
boiling point of mercury, it cannot be measured by a 



TO CHEMISTRY. 49 

common thermometer, because the mercury beginning to 
be volatilized,would burst the tube. Therefore,when any 
very high temperatures are to be measured, an instrument 
called a pyrometer is used for the purpose, that of Wedg- 
wood's has been considered as the most convenient, it is 
made of a certain composition of baked clay, which has 
the peculiar property of contracting by heat, so that the 
degrees of contraction indicate the temperature to which 
it is exposed. 

Observation. — In Wedgwood^s pyrometer, the dimen- 
sions of a piece of clay are measured by a scale graduat- 
ed on the side of a tapered groove, formed in a brass 
ruler ; the more the clay is contracted by the heat, 
the farther it will descend into the narrow part of the 
groove. 

47. All elastic fluids whatever undergo the same de- 
gree of expansion from equal augmentations of tempe- 
rature. 

48. Elastic fluids vary in density more than liquids or 
solids ; the uniformity of their expansibility, may be eas- 
ily accounted for, on the following principle. If the dif- 
ferent susceptibilities of expansion of bodies arise from 
their various degrees of attraction of cohesion, no such 
difference can be expected in elastic fluids, since in them 
the attraction of cohesion does not exist, their particles, 
on the contrary, being possessed of an elastic or repul- 
sive power; they will, therefore, all be expanded by 
equal degrees of caloric. 

49. Uncombined caloric has a tendency to any equi- 
librium ; any number of different bodies, at various de- 
grees of temperature, if placed under similar circum- 
stances of exposure, acquire a common temperature. 

Illustration — If there be placed in an atmosphere of 
5 



50 INTRODUCTION 

55°, iron filings made red hot, boiling water, and other 
substances of different degrees of temperature, they will 
all soon become of the same temperature, which may be 
indicated by the thermometer. 

50. Cold is a negative quality, and implies the ab- 
sence of heat. 

Illustration. — Some bodies appear cold to the touch, as 
quicksilver, marble, &c. This consists ia the loss of cal- 
oric, which that part of the body sustains which comes 
in contact with the cold body, in an attempt to bring 
the temperature to an equilibrium. 

51. According to a late theory, caloric is composed 
of particles perfectly separate from each other, every 
one of which moves with great velocity in a certain di~ 
rection. These directions vary infinitely, the result of 
which is, that there are rays or lines of these particles, 
moving with immense velocity, in every possible direc- 
tion. Caloric then is universally diffused, so that when 
any portion of space happens to be in the neighbourhood 
of another, which contains more caloric, the colder por- 
tion receives a quantity of calorific rays from the latter 
sufficient to restore an equilibrium of temperature. This 
radiation not only takes place in free space, but extends 
also to bodies of every kind. Thus you may suppose 
that every body whatever, is continually sending forth 
rays, when the body is surrounded with an elastic medi- 
um, or in a vacuum. 

52. These rays are capable of reflection and refrac- 
tion. 

Observation. It is well known that the concentration 
of the solar beams, by means of a concave mirror, is ca- 
pable of producing an intense heat. 

53. Rays capable of producing heat with or without 
light, proceed from substances on the surface of the globe, 



TO CHEMISTRY, hi 

ks well as from the sun, under peculiar existing circum- 
stances. 

Exp. 1. The effect is observed by placing two con- 
cave mirrors one above the other, between which are an 
ignited body and the thermometer. 

Exp. 2. Place the concave mirrors opposite each oth- 
er, with the edges of their faces perpendicular to the sur- 
face of the earth, and place an iron bullet about two inch- 
es in diameter, heated to a degree not sufficient to ren- 
der it luminous, in the focus of one of the mirrors, in the 
focus of the second mirror, place one of the bulbs of the 
differential thermometer, the rays which fall on the first 
mirror, are reflected in a parallel direction so as to fall 
on the other mirror, which may be placed at the distance 
of about ten feet, thence they converge to a focus, and 
affect very sensibly the thermometer. 

Exp. 3. Remove the thermometer and place instead 
of it a wax candle with a small piece of phosphorus in the 
wick, and after heating the ball, place it in its former 
place, the candle is immediately lighted. 

Exp. 4. Substitute a wax taper instead of the bullet, 
with a view to separate the light from the caloric ; for 
this purpose interpose a transparent plate of glass be- 
tween the mirrors, for light passes with great facility 
through glass, whilst the transmission of caloric is almost 
wholly impeded by it. But in this experiment, some few 
of the calorific rays, together with the light, pass through 
the glass as the thermometer rises a little, but as 
soon as the glass is removed, it will rise considerably 
higher. 

54. In cases where no light is emitted from a hot 
body, the effect of the radiation of CEiloric by the mirrors 
may still be produced. 

Exp. Let a vessel of boiling water be placed in the 



&S3 INTRODUCTION 

focus of the upper mirror ; place a thermometer m the 
focus of the lower one, a considerable increase of tempe- 
rature will be indicated. 

55. The manner in which bodies are affected by rays 
producing heat, differ in different substances, and is very 
much connected with their colours. 

56. Bodies that absorb the most light and of course 
radiate heat, are heated the most when exposed to the 
solar or terrestrial rays. 

Illustration 1. Black bodies in general are more heat- 
ed than red, red more than green, green more than yel- 
low, yellow more than white. 

2. Metals are less heated than earthy or stony mat- 
ters, or than animal or vegetable matters. Polished 
and bright surfaces are less heated than rough ones. 

57. Bodies that have their temperature most easily 
raised by the action of rays producing heat, are those 
most easily cooled by their radiation, or at the same tem- 
perature emit the most caloric. 

58. Metals radiate less heat than glass, glass less than 
some vegetable substances, and charcoal possesses the 
highest radiating power of any substance hitherto sub- 
mitted to experiment. 

Observation, Mr. Leslie has made a variety of experi- 
ments on the radiating powers of different substances: he 
found by assuming 1 00 for the radiating power of lamp 
black, the following substances radiated in proportion x 
riz. : 

Sealing Wax, 95 

Crown Glass, 90 

China Ink, 83 

Minium, 80 

Isinglass, 80 

Plumbago, 75 



TO CHEMISTRY. 53 

Tarnished Lead, 45 

Polished Iron, 15 

Tin Plate, Gold, Sil- } Jg 
ver and copper, S 
59. Vessels that are intended to contain much heat, 
should be well polished and bright. Steam or air pipes 
intended for warming rooms, should be polished in those 
parts where the heat is not intended to be communicated, 
and covered with some radiating substance, such as lamp 
black or plumbago, in those rooms intended to be heated. 
Vessels for the kitchen should be blackened and not pol- 
ished in those parts intended to receive heat. The heat- 
ed surfaces of stoves and fire places should not be metal- 
lic, but of stony or earthy materials ; in this way much 
more heat may be communicated hy radiation. 

60. The following principles are deduced from the 
observations of Mr. Leslie . . 

1. The quantity of heat which radiates from any 
body, depends in a great part on the surface of the body.. 
If the body be covered with black paint, paper, &c. it 
will radiate eight times as much heat as if the surface 
were metallic. 

2. If the bulb of a thermometer be covered with tin foil, 
the impression of radiant heat upon it is only 1-5 of what 
it would be on the glass surface of the thermometer. 

3. A metallic mirror reflects ten times as much heat 
from an ordinary fire, or from any heated body, as a sim- 
ilar glass mirror does, the last reflects the heat from the 
anterior surface and not from the silvered one. This cir- 
cumstance exhibits the difference between solar and cu- 
linary heat. From these facts it seems that metals are 
eminently disposed to reflect radiant heat, and of course 
not to absorb it, whereas black paint, paper, glass, &c, 
are disposed to absorb and not to reflect it; but when the 

5* 



54 INTRODUCTION 

temperature is increased, they are eminently disposed to 
radiate heat. 

4. Screens of glass being- interposed between the ra- 
diating body and reflector, completely interrupt the ra- 
diant heat ; but when heated by the direct radiant heat. 
the thermometer will be affected by their radiation 
The heat radiated from hot water does not seem capable 
of being transmitted through glass like the solar heat. 

5. Radiant heat suffers no sensible loss in its passage 
through the air, a greater or less radiant body produces 
the same effect, provided it subtends the same angle, at 
the reflector, agreeing with light in this respect. 

6. The intensity of reflected heat diminishes inverse- 
ly as the distance, that is, the density of heat reflected 
from a concave mirror in any point of the focus, is in^ 
versely as the distance of the hot body from the mirror, 
whereas in regard to light, the density is known to be 
uniformly the same, or subject to no change on account of 
distance. The focus of heat differs from that of light, 
being nearer the reflector. The heating effect diminish- 
es rapidly in going out, but slowly inwards towards the 
reflector. 

7. The quantity of heat which a strong radiating 
surface throws off, is somewhat more than that which 
is carried off by the atmosphere. This however is 
contradicted by some. 

PRACTICAL QUESTIONS. 

What is light? 

How have some considered light ? 
What best comports with our ideas of it ? 
What follows on the supposition of its being matter ? 
W T hat is its velocity ? 

How long is it in passing a semi-diameter of the earth's 
orbit? 



, TO CHEMISTRY. 55 

What are the momenta of the particles of light ? 

What calculations have been made with regard to the 
momenta ? 

What with regard to the minuteness of the particles ? 

Is light homogeneous ? 

What is the rarity of the rays of light ? 

Illustrate this. 

Do the rays differ from each other in their illuminating 
power ? 

Does it have any effect on inflammable substances ? 
*Give an illustration. 

What are phosphorescent bodies ? 

Give an illustration. 

How will you prove it ? 

What is the light emitted from animal and vegetable 
substances in a state of decomposition ? 

Do any living animals possess this property ? 

What is the chemical agency of light? 

Give an illustration. 

What effect does the shade have on plants ? 

Has light any influence on the colour of animals? 

Illustrate it. 

How have the solar rays been divided ? 

What is their intensity ? 

What effect have almost all bodies on the rays ? 

What are the sources of light ? 

Give an illustration. 

Give an illustration of percussion. 

What is denominated heat ? 

What is effected by this powerful agent ? 

What are the states in which caloric exists \ 

What is combined caloric ? 

How does heat differ from caloric ? 

Give an illustration. * •? 



56 INTRODUCTION 

What effect has it on water ? 

Illustrate it.. 

What is called temperature ? 

How do you infer that the particles of solid bodies are' 
not in contact ? 

What instruments have been invented for measuring: 
the degrees of heat ? 

What do the states in which bodies exist admit of ? 

How can bodies be of different degrees of consistence, 
without changing their state ? 

Give an illustration. 

How do you prove that fluids are more susceptible of 
dilatation than solids ? 

Is the degree of expansion the same in different li- 
quids ? 

Illustrate this by experiment. 

What does the boiling point mean in a thermometer ? 

How are thermometers constructed ? 

How is the centigrade thermometer divided ? 

How is Reaumur's ? How the Russian ? 

What fluids have been used for thermometers ? 

Describe air thermometers. 

Describe Mr. Leslie's air thermometer ? 

Why is it called a differential thermometer ? 

Will mercury answer for all temperatures ? 

Describe Wedgwood's pyrometer. 

In equal augmentation of temperature, what do elastic 
fluids undergo ? 

How do you account for the uniformity of their expan- 
sibility ? 

What tendency has uncombined caloric ? 

Illustrate this. 

What is cold ? 

Give an illustration. 



TO CHEMISTRY 57 

What is the theory of radiation ? 

Of what are these rays capable ? 

Whence do rays, capable of producing heat with or 
without light, proceed ? 

Illustrate this by experiments. 

What is the effect in cases where no light is emitted 
from a hot body ? 

Illustrate this by experiment. 

What is the manner in which bodies are aifected by 
rays producing heat ? 

When are bodies which absorb the most light, heated 
the most ? 

Give an illustration. 

What bodies are most easily cooled by their radiation ? 

What is the degree of radiation of different substances ? 

What is the radiating power of different substances ? 

How should vessels be made that are designed to coi> 
tain much heat ? 

What are the observations deduced from Mr, Leslie's 
experiments ? 



CHAP. IV. 

Continuation of Caloric. 

1. All bodies are, in a greater or less degree, con- 
ductors of caloric. 

2. Bodies with respect to caloric are divided into two 
kinds, good and bad conductors, 

Illustration 1, Metals and liquids are good conductors 
of caloric, but silk, cotton, wool, wood, feathers, down, 
&c. are bad conductor?: 



a8 x HfTRODUCTION 

2; A short poker or other piece of iron put into the 
fire at one end. will very soon become hot at the other ; 
but a piece of wood or cane of the same length, placed 
in precisely the same circumstances, may be burnt to 
ashes at one end, without producing scarcely a sensation 
of warmth at the other. 

3. The facility with which bodies are cooled or heat- 
ed, is in proportion to their conducting power 

Illustration, A silken purse containing money, when 
held to the fire, scarcely becomes warm, while the mon- 
ey becomes so hot as hardly to be touched, without burn- 
ing the hand. 

4. Brittle bodies are in general bad conductors of 
heat ; hence the surface to which heat is suddenly appli- 
ed by inordinate expansion, produces fracture. 

Observation. On this account, vessels made of glass 
and used over lamps, or exposed in any way to the nak- 
ed fire, should be as thin as possible, provided they be of 
sufficient strength to bear their contents. 

5. Solid bodies transmit caloric in all directions. 
Exp. Provide an iron or any other metallic substance, 

having bars or radii, proceeding from a centre, heat this 
centre, and you will find that the radii are equally heat- 
ed. 

6. Some bodies conduct caloric more rapidly than 
others, and this conducting power is not fully accounted 
for. It has been conjectured that a certain union takes 
place between the caloric and the particles of the body 
through which it passes. If this union be strong, the 
body retains the heat, and parts with it slowly ; if slight, 
it parts with it rapidly. The conducting power of a 
body is, therefore, inversely as its tendency to unite with 
caloric. 



*T0 CKOaS"r!VY. 5jj 

Exp. 1. Coat rods of iron and glass, of equal lengthy 
with wax at one end, and expose the other ends to the 
Same temperature, the wax will melt much sooner at the 
end of the iron than the glass, which shews that iron con- 
ducts heat more rapidly than glass. 

Exp. 2. Take rods of different metals and other sul> 
stances, and place them in the same circumstances as in 
the ahove experiment, or pfece them in a tin vessel till- 
ed with oil, and provided with holes to receive the un- 
coated ends ; apply a lamp under the vessel and as the 
liquid begins to heat, and consequently the rods, you 
will find that they all possess different conducting pow- 
ers, the wax beginning to melt at different periods. 

7. Good conductors both give and receive caloric 
quicker, and in a given time more abundantly, than bad 
conductors, which is the cause of their feeling hotter or 
colder ; though they may be in fact of the same tempera" 
lure, as indicated by the thermometer. 

Illustration 1. Different substances in the same room, 
at equal distances from the fire, are of the same tempera- 
ture ; a mahogany table will feel much colder to the 
hand, than a woollen carpet, but as the table is the best 
conductor of caloric, it will absorb the heat from the 
hand more rapidly, and of course feel much colder than 
the carpet, which is a very bad conductor. 

2. If the table and carpet were heated an equal num- 
ber of degrees above the temperature of *the body, the 
table would feel the hottest ; for as it took the heat more 
rapidly in the first instance from the hand, it will now 
impart it more rapidly to it. Because a body which is a 
good conductor of caloric affords it a free passage, so 
that it penetrates through that body more rapidly than 
through one which is a bad conductor, consequently, if it 
be colder than the hand, there is more caloric lost, and 



GO INTRODUCTION 

if it be hotter, more is gained by the hand, than with a 
bad conducter of the same temperature. 

8. If different conductors be heated to the tempera- 
ture of the body, they will all feel equally warm, because 
the exchange of caloric between bodies of the same tem- 
perature is equal. 

9. Flannel clothing is warmer in winter than linen, 
because flannel being a bad conductor keeps in the heat; 
and when the atmosphere is of a higher temperature 
than our bodies, it would be equally efficacious in keep- 
ing their temperature at the same degree, as it would 
prevent the free access of external heat by the difficulty 
with which it conducts it. 

Illustration, On the above principle it is that ice may 
be kept in warm weather longer wrapped up in woollen 
cloths, than in linen. 

10. In general, the most dense bodies are the best 
conductors of heat ; probably, because the denser the 
body, the more the number of points that come in con- 
tact with caloric. 

Illustration* At the common temperature of the at- 
mosphere, a piece of polished metal will feel much cold- 
er than wood ; and wood than a piece of woollen cloth ; 
this, than flannel, and flannel than eider down, which is 
one of the worst conductors of caloric known. 

11. Air is a bad conductor of caloric, hence porous 
bodies being tilled with air, become bad conductors. 

12. The conducting power of fluids of different den- 
sities varies, hence the reason why water feels much 
colder than spirits. 

Illustration. Mercury to the touch feels remarkably 
cold, but when a thermometer is applied to it, it is found 
to be of the same temperature as the surrounding atmo?~ 
phere. 



TO CHEMISTRV. 61 

13. Fluids have the power of transporting caloric, in 
-consequence of which, they acquire heat much more 
rapidly than solids, independent of any conducting power. 

14. Fluids necessarily contain more latent or combin- 
ed heat than -solids, but as the capacity of bodies for ca- 
loric is increased, their conducting power seems to be 
diminished, as in the case of liquids and gases, which ap- 
pear to be such bad conductors of heat, that Count Rum- 
ford supposed this power was only communicated by the 
interchange of heated particles. 

Exp. 1. Hot water on the surface of cold water in a 
tube, will remain long at the same temperature, but when 
disposed at the bottom, the whole becomes heated. 

2. Place a flask of cold water over the flame of a 
lamp, the heat expands and renders the water of less 
specific gravit} r , at the bottom of the vessel, which por- 
tion of water ascends to the top, while another of equal 
volume being colder and consequently heavier, bulk for 
bulk, falls to the bottom, and in this way there is a con- 
stant circulation from the bottom to the upper part of 
the vessel hence the theory of ebullition. 

3. Place a quantity of ice on the surface of a vessel 
of hot water, it becomes very soon melted ; but when 
placed at the bottom, it requires eighty times as long to 
fuse it. 

15. Freezing is a disengagement of that portion of 
caloric which is necessary to keep a substance in the 
state of liquidity. 

16. The quantity of caloric disengaged during the 
congelation of any substance is extremely slow. 

17. The constant emission of caloric from the freez- 
ing substance, operates favourably, for in this way the 
severity of the frost is mitigated, and its progress retard- 
ed. 

6 



0£ INTRODUCTION 

Observation 1. On this principle it is, that it often feels 
warmer after a great fall of snow. 

2. On the other hand, if the return of caloric to the 
frozen body of water were not equally slow, sudden in- 
conveniences would he occasioned in those countries 
where large masses of ice were collected, at the ap- 
proach of summer. 

18. Deep lakes do not freeze in winter. 
Illustration 1 . This is owing to the circumstance of cold 

air being constantly presented to the surface of the lake, 
which causes a portion of water to lose its temperature, 
and thus becoming heavier, falls gradually to the bottom, 
while the warmer water from below ascends, forming a 
new surface in its place. 

2. The temperature of the whole bulk of water in a 
deep lake is lowered, but only the surface descends to 
the freezing point. The diminution of heat produces a 
contraction in liquids as well as solids. This effect, how- 
ever, does not take place in water below 40 degrees, 
which is 8 degrees above the freezing point. At that 
temperature, the internal motion occasioned by the in- 
creased specific gravity of the condensed particles ceases ; 
for when the water at the surface no longer condenses, it 
will not descend, of course, a fresh portion will not be 
exposed to the atmosphere ; the surface alone will be 
further exposed to the severity, and will soon be brought 
down to the freezing point, when it becomes ice, which 
being a bad conductor of heat, preserves the water for a 
long time from being further affected by the external 
cold. 

19. Water swells on being frozen, in consequence of 
the extrication of a portion of air which it held in solu- 
tion, and which is disengaged in freezing. This air 
ibrms those numerous cavities which are found in ice ; 



TO CHEMISTRY. 6o 

nnd from the frozen particles receiving a different ar- 
rangement and requiring more room. 

20. Water in freezing, crystallizes in angles of 60° 
and 120°. 

Illustration. On this principle trees and rocks are 
split. A spherule of water,one inch in diameter, expands 
on freezing, with a force equal to thirteen and a half 
tons weight. 

Exp. Fill a phial with water, cork it and secure the 
cork with a pack thread ; on freezing, the phial is brok* 
en. 

21. The chemical effects of caloric in melting or fus- 
ing metals, earths, and other solid bodies, are equally 
striking with its effects in expanding or heating fluids. 

22. No substance can be expanded beyond a certain 
limit, during which time its specific gravity diminishes > 
and its temperature increases. 

Exp. Expose ice and ice cold water to the same degree 
of heat, the ice will not become hotter, but the water 
will. When, however, the ice is entirely melted, it will 
increase in its temperature with the water. 

23. In bodies which expand, there is a regular in- 
crease and contraction of bulk, according to the degree 
of heat. 

24. All solids which are not decomposed by caloric 
alone, fuse at a determinate point, which point is term- 
ed their melting point. No two substances fuse at the 
same temperature. 

25. All bodies require a certain temperature for their 
liquidity. Many are solid at that of the atmosphere. 

Illustration. Solids when fused by an excess of heat, 
gradually concrete on being exposed to the ordinary at- 
mosphere. 



64 INTRODUCTION 

26. Some bodies, such as earths, stones^ &c. melt into 
masses like glass, this is called vitrification. But reduc- 
ing* metals from a solid to a fluid, is called fusion. 

27. Caloric dissolves water and converts it into va- 
pour or steam, by insinuating itself between the particles 
which are so minutely divided as to become invisible* 

Illustration. When vapour of boiling water first issues 
from the vessel, it is invisible, because it is then com- 
pletely dissolved by caloric. But when it comes in con- 
tact with the cold air, it is condensed, in consequence of 
a part of the caloric being imparted to the air. The 
particles of caloric being in a great measure deprived of 
their solvent, gradually collect, and become visible in the 
form of steam, and when further deprived of caloric re- 
turn to their liquid state. 

28. The atmosphere dissolves water by means of the 
caloric which it contains. This is called evaporation, 
and differs from vaporization^ which is caused by culinary 
heat. 

29. The point at which a fluid is converted into va- 
pour depends upon a certain degree of temperature, cal- 
led the boiling point ; the boiling point of water on Fah- 

, renheit's scale is at 212°, and the freezing at 32°. 

30. The tendency of free caloric to an equilibrium, 
together with its solvent powers, are connected with the 
phenomena of rain, dew, &c. 

31. Dew is a deposition of watery particles, or mi- 
nute drops from the atmosphere, precipitated by the cool- 
ness of the evening. 

Illustration 1. Dr. Wells has shewn by a series of in- 
genious experiments, that the deposition of dew is owing 
to the cooling of the surface of the earth, which he has 
proved, takes place previously to the cooling of the at- 
mosphere ; on examining the temperature of a plot of 



TO CHEMISTRY. 65 

grass just before the clew fell, he found that it was con- 
siderably colder than the air a few feet above it, from 
which the dew was afterwards precipitated. 

2. The earth being a great radiator of caloric, parts 
with its heat more readily than the air. When the solar 
heat declines and entirely ceases in the evening, the 
earth rapidly cools by radiating heat towards the skies ; 
whilst the air has no means of parting with its heat, but 
by comings in contact with the cool surface of the earth, 
to which it communicates its caloric. The solvent pow- 
er being thus reduced, the water is deposited in small 
drops called dew. 

32. Some liquids contain so great a quantity of caloric 
that they may be rapidly converted into vapour without 
any increase of temperature, by removing the pressure of 
the atmosphere. It is that alone which keeps them. in a 
liquid state ; for the caloric they contain is -sufficient to 
overcome the attraction of cohesion. 

Exp. 1. Pour a little sulphuric ether into a cup, and 
place it under the receiver of an air pump, together with 
a small thermometer, and on exhausting the air, the ether 
has the appearance of boiling, and the thermometer de- 
scends. . 

2. Take two watch glasses^ and having placed one 
over the other with a few drops of water between them; 
fill the uppermost glass with ether, and place them in the 
room of the cup as in the above experiment ; work the 
pump for two or three minutes, and a thin layer of ice 
will be found between the glasses. The water freezes 
in consequence of yielding its caloric to the ether. 

33. In order that a liquid may boil, there are two 
forces to be overcome; the attraction of aggregation* 
and the weight of the atmosphere, 



I 5 INTRODUCTION 

On high mountains much less Lea: is ne- 
cessary to cause liquids to boil, than at the bases, where 
the pressure of the atmosphere is less. 

Exp. Take a Florence flaak about half full of water. 
and when in the act of boiling- take it from the tire, -wrap 
a cold wet linen cloth round the upper part of it. or cork 
it, plunge it into cold water, and it will immediately he- 
gin io boil. 

The upper part of the Cask being fil 
with vapour, this was condensed by its caloric being com- 
pelled to unite with that of the water, ol course a vacu- 
um being produced, it boiled in a much lower tempera- 
ture. 

Si. If water can be prevented from going off by 
steam, it will acquire a degree of heat equal to that of 
Eals when red hot. 

A vessel used for this purpose is called 
Papia'fl digester, and is a copper vessel half filled with 
r. The vessel is furnished with a safety valve, 
loaded with weights. Vv'hen the water is so hot as to 
send off vapour, its escape is prevented until it has ac- 
quired force almost great enough to burst the vessel, 
when it raises the valve, which prevents it. Lead and 
tio have leen fused in the water of this vessel^ aad 
\ ones have been totally dissolved. 

35. Water does not become hotter by being boiled 
long in the common way ; after arriving at the boiling 
point, the heat gradually converts a portion of the water 
into vapour, and the additional heat applied, goes or! 
with the vapour. 

36. Ignition is that emission of light which is produc- 
ed in bodies at a very high temperature, and which is 
the eneet of accumulated caloric. 



TO CHEMISTRY. O t 

37. Ignition is independent of combustion. When a 

body burns, the light emitted is the effect of caloric alone, 
and no other change but that of temperature is produced 
in the ignited body. 

Illustration. All solid bodies and liquids are suscepti- 
ble of ignition, or of being heated so as to become lumi- 
nous. 

PRACTICAL QUESTIONS. 

What bodies are conductors of caloric ? 

How are bodies divided with respect to caloric ? 

Give an illustration, 

What is the facility with which bodies are cooled ov 
heated ? 

Illustrate this. 

How do solid bodies transmit caloric ? 

What is the conducting power of some bodies '? 

Illustrate this by an experiment. 

What is the cause of good conductors of caloric feel- 
ing hotter or colder ? 

Illustrate this. 

Why is flannel clothing warmer in winter than linen ? 

What bodies are the best conductors of heat, and why ? 

Illustrate this. 

Why are porous bodies bad conductors ? 

Is the conducting power of all fluids the same ? ; 

Illustrate this. 

Why do fluids acquire heat quicker than solids ? 

Illustrate this. 

What experiments can you shew to prove the truth of 
the proposition ? 

What is freezing ? 

What effect does the constant emission of caloric, from 
the freezing body, have ? 



60 INTRODUCTION 

Why is it that deep lakes do not freeze in winter.?.: 

Why does water swell on being frozen ? 

How does water crystallize in: freezing*? 

Illustrate this. 

How are the chemical effects of caloric ? 

How far caa substances be expanded ? 

How is the increase and contraction of bulk in bodies, 
that expand ? • 

What do bodies require for their liquidity ? 

Horn, is water converted into vapour or steam V 

Illustrate -this. 

How does the atmosphere dissolve water ? 

Upon what does the conversion of a fluid into vapour 
depend ? 

With what is the tendency of caloric to an equilibrium, 
attended? 

What is dew ?'.- 

Explain this on Dr. Wells' theory ? 

How can liquids that contain a large portion of caloric 
be converted into vapour ? 

What is neccessary in order to a liquid's boiling ? 

Illustrate this. 

What will be the effect, if boiling water be prevented 
from going off in steam ? 

Illustrate this. 

Can water be made hotter by being continued boiling ? 

What is ignition ? 

How does ignition differ from combustion ? 



T© CH£MXSTR¥. 69 

CHAP. V. r 

Of coinbinzd Caloric — Specific and Latent Heat. 

1. Bodies of a different nature, heated to the same 
temperature, do not contain the same quantity of caloric. 

2. In order to raise the temperature of different bo- 
dies the same number of degrees, different quantities of 
caloric are required. 

Illustration. If lead,chalk and milk of each equal weights 
be placed in a hot oven, or furnace, they will be gradu- 
ally heated to the temperature of the oven ; but the 
lead first, the chalk next, and the milk last. This is 
probably owing to the different capacities of bodies for 
caloric. 

3. Capacity for caloric is a certain disposition of bo- 
dies to require more or less caloric for raising their tem- 
perature to a certain degree. 

Illustration. The meaning is pretty nearly the same 
as when the term is applied to vessels ; in these, the ca- 
pacity is greatest in that which will contain most ; so it 
is with regard to caloric. Thus iron has a less ca- 
pacity for caloric than wood, and quicksilver has a less 
capacity for it than water ; because it requires a smaller 
quantity of it to raise its temperature to a given degree 
on the thermometer. 

4. The caloric that is employed in filling the capaci- 
ty of a body is not free caloric, but is combined in the 
body, and is, therefore, imperceptible. 

Illustration. If you lay your hand on a hot body, you 
feel only the caloric that leaves it and enters your hand. 
The thermometer in the same manner is affected only 
by the free caloric which a body transmits to it, 



70 INTRODUCTION 

5. Specific caloric is the relative quantity of caloric^ 
which different species of bodies of the same weight and 
temperature are capable of containing ; it is often called 
heat of capacity. , 

Illustration 1. In the case of the lead, chalk and milk, 
the two latter having a greater capacity for caloric than 
the lead, a greater proportion of that fluid became insen- 
sible in those bodies. 

2. The difference could not proceed from the differ- 
ent conducting powers in those bodies, for if the different 
times they took in heating.prcceeded fromTtheir different 
conducting powers, they would each have acquired an 
equal quantity of caloric. This we shall shew is not 
the case, 

Exp. Plunge the lead, chalk and milk, into three 
equal quantities of water, each of the same temperature, 
on examining the three vessels of water you find the one 
in which the lead was immersed to be least heated, and 
that which contained the milk to be most heated of all. 

5. The thermometer indicates no specific heat of bod- 
ies, for it can only be affected by free caloric which raises 
the temperature of bodies. 

Exp. 1. Mix two fluids of different temperatures, let 
the one be 50° and the other 100°. If the two bodies 
happen to have the same capacity for caloric, the temfe*- 
rature will be 75°. 

2. Mix a pound of mercury at 50°, and a pound of 
water at 100°, the capacity of the two substances not be- 
ing equal, the temperature of the mixture will be 
80°, so that the water will have lost only 12 degrees, and 
the mercury will gain 38 degrees. Hence it may be in- 
ferred that the capacity of mercury for keafr is less thaa 
that of water. 



to ciiLMisin'r. 7 t 

6. Latent heat is that portion of caloric which is em- 
ployed in changing the state of bodies, or in converting 
solids into liquids, or liquids into vapour. 

Observation. By most chemists it is used in the same 
sense as speciiic caloric. 

7. When a body changes its state from a solid to a 
liquid, or from a liquid to a solid, its expansion occasions 
a sudden and considerable increase of capacity for heat, 
consequently it immediately absorbs a quantity of caloric, 
which becomes fixed in the body which it has transform- 
ed, and as it is perfectly concealed from our senses, it has 
obtained the name of latent heat. 

3. The difference between speciiic and latent heat is 
this, the former is that which is employed in tilling the 
capacity of a body for caloric in the state in which this 
body actually exists ; latent heat is that which is employ- 
ed only in effecting^ change of state. 

Exp. The mercury of a thermometer plunged into a 
vessel filled with pounded ice will immediately descend 
to 32° If then the vessel be immersed in boiling wat- 
er, the mercury will not rise during the whole time that 
the ice is liquefying. 

Illustration. The heat which is continually flowing in- 
to the ice does not affect the thermometer, because it is 
all employed in converting ice into water As the ice 
melts, the caloric becomes latent in the new formed li- 
quid, therefore cannot raise its temperature, consequent- 
ly the thermometer will remain stationary until the whole 
of the ice be melted. It will then begin to rise because 
the caloric no longer remains latent, but free. 

9. The capacity of water for caloric is greater than 
that of ice, more heat is therefore required to raise a 
thermometer plunged into water than when placed in ice 
or snow. 



72 INTRODUCTION 

Exp. Put some snow or pounded ice which has been 
cooled 7 or 8 degrees below the freezing point into a 
glass vessel, in which there is a thermometer ; apply the 
heat of a lamp and the mercury will rise gradually 
to 32°, where it will remain stationary until the whole is 
melted, when it will again rise, though much slower. 
It continues to rise until the water begins to boil, when 
it again becomes stationary. The caloric is now no long- 
er free to affect the thermometer, but is employed in 
converting the water into steam, in which it becomes 
stationary. This is sometimes called caloric of fluidity, 
or evaporation. 

10. When a body passes from a liquid to a solid, or 
from vapour to a liquid, the latent caloric is evolved and 
becomes free. 

Illustration. When water, as in the slacking of lime, is 
converted from a liquid to the solid state, the caloric 
which caused the water to continue fluid is evolved and 
the sensible or free caloric is increased. 

11. When a body is condensed or has its volume di- 
minished, whether by mechanical force, as in condensing 
the air in the receiver of an air pump, metals under the 
hammer,&c. or by chemical combination, in which concen- 
tration takes place, the latent caloric is pressed out, and 
consequently, the sensible or free caloric is increased. 

Exp. Fill a wine glass about half with water, and 
pour upon it sulphuric acid, a very high temperature 
is produced, which is caused by the disengagement of 
latent caloric. 

2. Pour into a phial containing a solution of muriate lime, 
a few drops of oil of vitriol, sulphuric acid, the whole will 
be converted into a solid mass, at the same time the bot- 
tle becomes very much heated. 

3. A cold bar of iron, by hammering on an anvil, may 
be made red hot. 



TO CHEMISTRY. 73 

4. Prepare a hot saturated solution of sulphate of so 
da, Glaubers salts, in a flask ; when it is hot, cork it, and 
keep it in this situation until cold. Then take out the cork 
and let the air into the vacuum made by corking it when 
the salt will suddenly crystallize, while at the same time, 
sensible heat is disengaged. 

1 2. When a body is rarefied or has its volume increas- 
ed, as in exhausting the air from the receiver of an air 
pump, the caloric is absorbed and the sensible heat is di- 
minished 

PRACTICAL QUESTIONS. 

Do all bodies contain the same quantity of caloric? 

How are different bodies raised to the same degree of 
temperature ? 

Give an illustration. 

What is capacity for caloric ? 

Illustrate it. 

What is the caloric that is employed in filling the ca- 
pacity of a body ? 

Illustrate it. 

What is specific caloric I 

Illustrate it ? 

May not the difference proceed from the different pow- 
ers of those hodies in conducting caloric ? 

Illustrate this by experiment. 

Does the thermometer indicate the specific heat of 
bodies? 

What is latent heat ? 

Why is it called latent heat ? 

What is the difference between specific and lateat 
lieat ? 

What is the capacity of water and ice for caloric ? 

Illustrate this by an experiment, 



74 INTRODUCTION 

When dees the latent caloric become free in bodies ? 
When is the sensible or free caloric increased ? 
Illustrate this by experiment. 
When is the sensible heat diminished ? 



CHAP. VL 

Of Oxygen and its combinations. 

1. Oxygen is the principle upon which most of the 
chemical phenomena of atmospheric air depend* 

Observation. Ox} r gen was discovered by Mayow, in 
1674, and called by him igneo-aerieal spirit. It was named 
dephlogisticated air by Dr. Priestley, who examined it in 
1774. Scheelein 1777, called it empyreal air; Condor- 
cet vital air ; and Lavoisier, oxygen, which term is now 
universally adapted by chemists. 

2. Oxygen has never been procured in an uncombin^ 
ed state. Its greatest purity is that of oxygen gas. 

3. The term Gas is given 'to any fluid capable of ex- 
isting in an aeriform state, under the pressure and tempe- 
rature of the atmosphere. 

4. Oxygen has never been made solid by any degree 
of cold, and therefore differs in this respect from vapours 
which may be condensed into a liquid, and converted in- 
to a solid. 

5. Sir H. Davy thinks that goses owe their perma- 
nently elastic state to the presence either of positive or 
negative electricity. — (see electricity.) 

6. Oxygen and oxygen gas are used as synonymous, 
though strxktly speaking, oxygen is the base of the gas 
known by tii at name, 



TO CHEMISTRY. 75 

7. Oxygen is one of the most important agents in na 
ture, it has a share in almost every process, either natu- 
ral or artificial. 

To procure oxygen gas in large quantities proceed as 
follows : Take an iron bottle or retort, (B. Plate 3, tig. 
l,)and having charged it with powdered black oxide of 
manganese, place it in the furnace, (A.) on a small stand 
above the grate, lute to the beak of the retort a tube 
(E.) passing under the jar (D.) which is filled with water 
standing on a shelf in the pneumatic cistern or water 
bath, C. Kindle a fire in the furnace, when the retort 
becomes red hot T the gas passes over and rises in the jar 
in the form of bubbles, displacing the water. 

Observation. . Instead of the black oxide of manganese, 
the red oxide of lead may be used., in that case a glass re- 
tort, and Argand's lamp may be substituted for the above, 
fig. 2, E F the lamp, C the retort, D the stand — e. e. e. 
rings with screws for holding the different vessels neces- 
sary in the use of this furnace,. 

8. Oxygen gas is permanently elastic, compressible, 
inodorous, transparent and insipid. 100 cubic inches at 
60° F ; barometer at 30 inches weighs 33.82. 

9.-. The specific gravity of oxygen in relation.to wa- 
ter, is as 0.00135 to 1.00000 ; and in relation to hydrogen 
as 15 to 1. In relation to an equal volume of atmos- 
pheric air as 1.1088 to 10000. 

10. Its specific caloric or capacity for heat is 0.8848 
to an equal bulk of atmospheric air as 1.0000. 

11. The specific heat of water being unity, that of 
exygen will be 0.2361. 

12. Oxygen gas is a supporter of combustion. The 
quantity of caloric liberated during combustion depends 
entirely on the quantity of oxygen gas combined in a giv- 
es* space of time with the combustible body. 



76 INTRODUCTION 

Exp. 1. Immerse an inflamed taper in oxygen gas, it 
burns with great splendour, and is much more rapidly 
consumed than in atmospheric air* 

2. Blow out the taper and when the wick is merely 
glowing, immerse it in oxygen gas, it is immediately re- 
kindled with a slight explosion. 

3. Bend a small steel or iron wire spirally, attach to 
it a piece of lighted tinder, and hnving placed it in a jar 
filled with oxygen gas, the metal will burn, with great 
brilliancy and throw off beautiful white scintillations 
which are iron combined with one portion of ox3 r gen now 
called protoxide of iron. 

4. If sulphur, phosphorus or charcoal be burned in 
oxygen gas, the combustion will be intensely vivid, and 
acids will be produced, of greater or less strength, accor- 
ding' to the proportion of oxygen they contain. 

Illustration. Phosphorus with a small portion of ox- 
ygen forms an oxide of phosphorus ; with a larger por- 
tion, phosphorus acid, and with the largest, phosphoric 
acid. 

13. Oxygen gas is the only one that can be breathed by 
animals for any length of time, with imp-rarity. The 
power of atmospheric air in supporting respiration is ow- 
ing to the oxygen. 

14. In respiration a quantity of atmospheric air is 
taken into the lungs, the oxygen disappears and a quan^ 
tity of carbonic acid gas equal in bulk is formed in ita 
stead. A reciprocal influence is exerted between this 
aerial fluid and the circulating blood, and the continuance 
of life is dependent upon the due exercise of this influx 
ence which appears by the conversion of oxygen into 
carbonic acid. 

\5, Animals Qpnfin^d in oxygen gas will live four or 



TO CHEMISTRY. 77 

five times longer than when confined in atmospheric 
air. 

16. It may be breathed by men for some time with- 
out producing any other effect than a sensation of 
warmth and slight stricture of the chest. 

17. Oxygen forms about 22 per cent of the atmospher- 
ic air, the rest is nitrogen or azotic gas^ except perhaps 
a small quantity of carbonic acid. 

18. With hydrogen it forms water in the proportion 
of eighty five oxygen, and fifteen hydrogen. Water 
which is perfectly insipid contains more oxygen than any 
of the acids to which it is essential. 

Illustration. When any fluid capable of undergoing fer- 
mentation is exposed to the atmosphere and in a moderate 
temperature, it absorbs oxygen and is changed to an acid, 

19. Oxygen is separated from many of its combina- 
tions by the influence of the solar rays ; especially from 
water, . 

^Exp. Place a tumbler of clear spring water in the 
rays of the sun for a few minutes, small bubbles of oxy- 
gen gas will be forxafcd/Sh the bottom and sides. 

20. Oxygen combines with all the metals, and in 
that state they are called metallic oxides, depriving them 
of their metallic lustre, and giving them an earthy or 
rusty appearance. 

21. Some of the metals become oxidized, or are rust- 
ed by mere exposure to a damp atmosphere. - 

Exp. Iron exposed to the weather soon becomes rus- 
ty by attracting oxygen from the air or water. 

22. All oxides are heavier than the metal, in propor- 
tion to the quantity of oxygen with which they are com- 
bined. 

23. Many of the metals are capable of combining 
with different proportions of oxygen. Those with one 

7* 



78 INTRODUCTION 

portion are called protoxide* ; of two, Deutoxides ; those of 
three, tritoxides. 

24. A metal combined with the greatest proportion of 
oxvgen is called peroxide. 

25. In general the least simple hases unite with oxy- 
gen in the greatest variety of proportions. 

26. Oxygen undergoes various changes in its prop- 
erties by its union with many oxidizable substances. The 
compounds are fluid, solid, opaque, coloured, incapable of 
supporting inflammation, and deleterious to animal and 
yegetable life. 

27. Oxygen has a powerful effect on vegetable col- 
ours, producing the various tints of shade which we be- 
hold in this department of nature- 

Illustration 1. Yarn when first taken from the blue vat r 
is-green, but on exposure to the air y it imbibes oxj'gen, 
and is changed to a deep blue. 

2. The Buccinum r which is employed in dying pur- 
ple, undergoes a remarkable change in contact with ox- 
ygen, the liquor naturally yellow, becomes oxidized on 
exposure to the sun and air; it passes through various 
shades of yellow, green, crimson, &,c. at length it becomes 
purple. 

3. It is well known to dyers that they cannot pro- 
duce a good black without exposing their stuffs to the 
air. 

23. Vegetable colours fade on exposure to the sun,, 
which is probably owing to this principle ; the oxygen, 
which previously existed in the colouring matter in a 
solid form, is rendered aeriform by the rays of the suiv 
and is evolved in the form of gas. 

29. Oxygen gas of great purity may be obtained from 
the green Leaves of plants ; Ingenhouz first obtained it 



TO CHEMISTRY. 7$* 

from these substances for some of his most brilliant ex- 
periments. 

30. It is obtained in the greatest purity from chloride 
of potassium, by simply decomposing it with a very gen- 
tle heat. This, however, is not an economical methods 

PRACTICAL QUESTIONS. 

What is oxygen ? 

Who discovered it, and what was it named V 

Has oxygen been obtained in its pure state ? 

What is gas ? 

How does it differ from vapour ? 

To what does Sir H. Davy suppose that gases owe 
their permanently elastic state ? 

What is oxygen j strictly speaking ? 

Of what use is oxygen in nature ? 

How is oxygen gas produced ?. 

What are the characteristics of oxygen gas ? 

What is its specific gravity ? 

Is oxygen gas a supporter of combustion ? 

On what does the quantity of caloric, during combus- 
tion, depend ? 

Illustrate it by experiment. 

What is the supporter of respiration ? 

Describe the process. 

What effect does oxygen gas have on animals, when 
confined in it ? 

What effect on man ? 

What proportion does it form of the atmosphere ? 

What proportion does it form of water? 

How is oxygen separated from many of its combine 
tions ? 

Does it combine with the metals ? 

How are some of the metals oxidized I 



80 INTRODUCTION 

What is the weight of the oxides ? 

Do the metals combine with different portions of oxy- 
gen, and what are those combinations called ? 

What is the greatest metallic oxide called ? 

Does oxygen undergo any changes in its combinations ?* 

Has oxygen any effect on vegetable colours ? 

Illustrate it. 

Why do vegetable colours fade, on exposure to the 
sun ? 

How can this gas of great purity be obtained ? 

From what is it obtained in the greatest purity ? 



CHAP. V2I. 

Of Azote or Nitrogen. 

1. Nitrogen is the basis of the nitric acid ; it exhibits- 
itself in its simplest state as a gas. 

Observation. This gas was discovered by Dr. Ruther- 
ford, in 1772, and by Mr. Scheele, 1776. It was former- 
ly called azote, because it was destructive to animal life. 

2. Nitrogen constitutes about 0.78 parts in bulk of 
atmospheric air. 

3. The use of nitrogen in atmospheric air is to dilute 
the oxygen gas, in order to render it adequate for the 
several functions which it is destined to perform in the 
economy of nature ; thus mollifying the activity of the 
latter, which in its pure state, would be too powerful. 

4. It may be readily obtained from atmospheric air r 
by removing the oxygenous part of it. 

Exp. 1. If a portion of iron filings and sulphur mois- 
tened with water,, be put into a flask filled with common 



TO CHEMISTRY. 31 

air, the oxygen will, in a short time, be absorbed by the 
metal and sulphur, while the nitrogen gas will remain. 

£. Phosphorus inclosed in a similar vessel with com- 
mon air, will produce a similar effect. The phosphorus 
will be oxidized or converted into phosphoric acid, while 
the nitrogen will remain. 

3. Under a bell glass which is full of atmospheric air, 
standing over water, introduce some suiphuret of potash, 
which in a few days will absorb all the oxygen and leave 
the nitrogen pure. 

4. Any kind of muscular flesh cut small, and put in a 
retort with some diluted nitric acid, will, by the applica- 
tion of heat, produce nitrogen gas. 

5. Nitrogen gas when pure is permanently elastict 
inodorous and insipid. It converts vegetable blues to 
green. It is fatal to animals confined m it. 

6. Nitrogen immediately extinguishes flame. 

Exp. Procure a jar of nitrogen gas and immerse in it 
a burning taper. It is immediately extinguished, as ef- 
fectually as if thrust into a vessel of water. 

7. When nitrogen gas is mixed with oxygen in the 
proportion of four parts of the former to one of the lat- 
ter, it produces a mixture resembling atmospheric air. 

8. The specific gravity of nitrogen to that of water 
is, as 0.0012 to 1.0000, and to that of hydrogen as 13 to 1, 

9. It dissolves phosphorus and carbon in small quan- 
tities. 

10. Nitrogen has been thought by some to be a com- 
pound of hydrogen and oxygen, containing a less propor- 
tion of oxygen than water, composed of 6 atoms hydros 
gen, and 1 oxygen, or by weight of 44.4 of the former, 
and 55.6 of the latter. But this fact, if it be one ? has 
pot been fully demonstrated. 



82 INTRODUCTION 

11. Nitrogen constitutes an ingredient in animal sub- 
stances, and this in some measure distinguishes them from 
vegetable ones, where it is very rarely found. 

12. Nitrogen unites with oxygen in two states ; in 
mixture, they constitute atmospheric air ; in chemical 
combination, the nitric acid, 

13. Nitrous acid is nitric acid holding nitr®us gas in 
solution, and is the aqua fortis of the shops. 

14. There are two combinations of nitrogen and oxy- 
gen in a gaseous state, viz. nitrous oxide and nitrous 
gas. 

15. Nitrogen combines with hydrogen and forms am- 
monia. 

PRACTICAL QUESTIONS. 

What is nitrogen ? 

Who discovered it, and when ? 

What proportion of the atmosphere does it constitute ? 

What is its use in the atmosphere ? 

How can it be obtained ? 

What are its characteristics ? 

Will it support 0ame ? 

How can you form atmospheric air I 

What is the specific gravity of hydrogen ? 

What does it dissolve ? 

What has it been considered to be by some ? 

How are animal substances distinguished from vegeta- 
ble, with regard to nitrogen ? 

In how many states does nitrogen unite with oxygen ? 

What is nitrous acid ? 

How many chemical combinations are there of ni 
irogen with oxygen ? 

What is ammonia ? 



ii> CHEMISTRY. 83 



CHAP. VIII. 

Of Hydrogen. 

1. Hydrogen united to caloric is one of the constitu- 
ents of water; it has never been obtained but in combi- 
nation with caloric, with which it forms nitrogen gas. 

Observation. Its properties were first examined in 
1756 by Mr, Cavendish. 

-2. It is one of the most abundant principles in nature ; 
it forms about 1-9 of all the water of the globe, and is a 
constituent of oil, bitumen, ardent spirits, ether, alcohol, 
and of all the component parts of animal and vegetable 
substances. 

3. Hydrogen is invisible and elastic, and between 12 
and 13 times lighter than common air; hence its use in 
filling balloons^ 

Exp. Fill a bladder with hydrogen, having a small 
aperture with a stop cock ; prepare a strong solution o? 
soap in water, and having fitted a tobacco pipe to the 
stop cock, dip it in the soap and water, and take up a 
few drops, having turned the cock, squeeze out some of 
the gas so as to form a bubble, which, when disengaged, 
will ascend rapidly to the ceiling of the room, like air 
balloons. 

4. This gas has a smell resembling garlic. It is ut- 
terly unfit to support respiration or combustion. 

Illustration. Although it may be taken into the lungs r 
it cannot be breathed by man for more than a minute ; 
small animals die in it, in a much shorter time. 

5. Its specific gravity to that of oxygen is as 1 to 16. 

6. Water is composed by weight of oxygen, 88.24, 
hydrogen, 11.76 in the 100, and may be obtained by 



84 INTRODUCTION 

combustion, in this way hydrogen combines with the 
oxygen, and their opposite electricities are disengaged in 
the form of caloric ; by the loss of caloric the two gases 
are condensed \ito a liquid. 

Illustration. In this process, the two gases are chem- 
ically combined and not mixed as is the case with ox} r - 
gen and nitrogen in atmospheric air. 

7. Hydrogen is obtained by the decomposition of wa- 
ter ; the best way of obtaining it for experiments is, as 
follows. Take sulphuric acid diluted with five or six 
times its weight of water, and pour it on a quantity of 
iron or zinc filings in a gas bottle, plate SLfig. 3, con- 
nected with a pneumatic cistern. An efiervesence takes 
place, and the hydrogen is evolved, which may be col- 
lected in a jar over water, while the oxygen unites with 
the metal and becomes solidified. The water is decom- 
posed in consequence of the great affinity of the metal 
for oxygen. If the metal be taken out and dried, it will 
be found to have gained in weight equal to the oxygen 
absorbed. 

Observation. It has been conjectured that hydrogen is 
a metal in an aerial form. 

8. Water may be decomposed by electricity, or the 
action of the voltaic battery. 

Exp. 1. Fill a piece of glass tube with water, plate 
3, fig. 3, and cork it at both ends ; through one of the 
corks introduce the positive wire of the battery, and the 
negative through the other, let the ends of the wires be 
about l-8th of an inch apart. Each wire decomposes the 
water, the positive by combining with its oxygen, which 
is negative, and the negative with the hydrogen, which 
h positive. The bubbles which appear to proceed from 
the positive wire, are the result of the decompos ton of 
water by that wire. For the positive electricity hav^ag 



TO CHEMISTRY. 85 

Combined with some of the oxygen of the water, the 
particles of hydrogen which were combined with that 
portion of oxygen, are set at liberty and appear in the 
form of small bubbles of gas. The negative fluid hav- 
ing in the same manner combined with some of the hy- 
drogen of the water, the particles of oxygen that were 
combined with it are set Free, and emitted in a gaseous 
form. 

Observation. The wires used in this experiment should 
be made of platina, which does not combine readily with 
oxygen, otherwise the oxygen would combine with the 
metal, and the hydrogen only would be disengaged. 

Exp. 1. The gases in the above experiment were 
mixed, but they may be collected separately, in the fol- 
lowing manner. Instead of one tube, let two be used, 
fig. 4, e. d. both tubes being closed at one end and open 
at the other ; fill these tubes with water, and place them 
standing in a glass of water e. with their open end down- 
wards ; connect the wires a. b. which proceed from the 
interior of each tube, the one with the positive, and the 
other with the negative end of the battery ; the water in 
the tubes will be decomposed, hydrogen will be given 
Out round the wire in the tube connected with the posi- 
tive end of the battery, and oxygen in the other ; the 
gases will be evolved exactly in the proportion of two 
measures of hydrogen to one of oxygen. 

Exp. 2. Water may be decomposed by means of heat 
in the following manner* Place a gun barrel across a 
furnace, inclining a little. To the extremity, lute on a 
small glass retort, containing a quantity of water, and to 
the other end is to be luted a tube connected with a pneu- 
matic cistern. Two fires are now to be lighted, one in 
the furnace, sufficient to keep the gun barrel red hot ; 
and the other in a lamp under the retort. When the 
8 



<86 INTRODUCTION 

water boils, the vapour will pass through the tube, where 
it will be decomposed ; the oxygen is attracted by the 
metal and the hydrogen is evolved and passes out of the 
tube, where it may be caught in jars, or inflamed at the 
mouth of the tube. 

9. From the combustion of oxygen and hydrogen, wa- 
ter is produced. 

Exp. Take the gases collected by the voltaic ex- 
periment No. 2, that is to say, two volumes of hydrogen, 
and one of oxygen, and having mixed them, set fire to 
them by an electric spark, both gases will entirely dis- 
appear, and a small quantity of water will be obtained. 

10. Hydrogen gas in combustion has the property of 
producing very peculiar sounds in glass. 

Exp. Provide a phial with a cork stopper, through 
w T hich, pass a glass tube or piece of the stem of a tobac- 
co pipe ; into this pipe, half filled with water, put a 
quantity of iron filings, to which, add of sulphuric acid a 
quantity equal to one third of the water. Replace the 
cork, and the hydrogen gas will be liberated through the 
tube, to which after the atmospheric air is disengaged, 
apply the flame of a candle, the hydrogen will immedi- 
ately take fire and burn with a clear flame. This has 
been named the philosophical candle. 

If a piece of glass tube about two feet in length and 
one inch in diameter, open at both ends, be placed over 
the flame, a noise similar in some measure to an Eolian 
harp will be produced 

Illustration, The cause of this is probably owing to a 
quick vibrating motion of the glass, occasioned by the 
successive formation and condensation of small drops of 
water on the sides of the glass tube, and the air rushing 
m to replace the vacuum formed, 



TO CHEMISTRY. 8*jf 

ri. The flame of a candle or lamp is produced by the 
hydrogen which is contained in the wax, tallow or oil, 
which being converted into gas by the heat of the can- 
dle, combines with the oxygen of the atmosphere, and 
flame and water result from the combination. The can- 
dle must come in contact with some ignited body in order 
to give the first impulse to the combustion, it afterwards 
goes on of itself, because the candle finds a supply of ca- 
loric in the successive quantities of heat which result 
from the union of the two electricities, given out by the 
gases during their combustion. 

12. Flame, in general, is owing to the formation and 
combustion of hydrogen gas, or rather hydro-carbonate t 
which is an union of hydrogen with carbon. 

13. The regular tapering shape of flame, is owing 
to the stream of hydrogen gas, which issues from the 
burning body ; the combustion of the gas is completed at 
the point where the flame terminates, it is there con- 
verted by its union with oxygen into aqueous vapour. 

Exp. Invert a tumbler over the flame of a candle, in 
a few minutes the inside becomes covered with vapour. 

14. Hydrogen gas when inflamed burns gradually, 
but when mixed with atmospheric air or oxygen, it de- 
tonates violently. 

Exp. 1. Fill a bladder, havings a stop cock, with hy- 
drogen gas, adjust to the cock a small pipe, dip this in 
soap suds, and having blown up bubbles, apply to them a 
burning taper, and a loud detonation will ensue. 

2. Fill a small jar or phial with a mixture of one 
pari of oxygen and two parts of hydrogen, and apply the 
mouth to the flams of a candle or taper, it will explode 
with a loud noise. 

Illustration. By the application of flame, the hydro* 
gen is decomposed or burnt, and forms water by it? chemi- 
cal union with oxygen. 



38 HVTRODUCTIOtf 

15. Hydrogen forms a constituent in pit coal, and 
may be disengaged or combined with carbon, called car- 
buretted hydrogen gas. 

16. Gas lights are produced from carburetted hydro- 
gen gas, conveyed through a tube of a very small bore, 
at the extremity of which, it is kindled and burns as long 
as the supply continues, without wick or any other sub- 
stance whatever, except the gas. 

Exp. Pulverize a small quantity of coal and put it in- 
to the bowl of a tobacco pipe, cover the coal closely over 
with clay and place the bowl in the fire. In a few min- 
utes a stream of carburetted hydrogen gas will issue from 
the end of the pipe, which may be inflamed with a light- 
ed taper, and will burn for a considerable time. 

Observation. On a large scale, the carburetted hydro- 
gen gas is obtained from coal in iron retorts, the gas at 
its formation is made to pass through two or three large 
vessels of water, in which it deposits foreign ingredients 
which are carried over with it from the retort, thence it 
is conveyed with uniform velocity by means of pressure, 
to the destined places. 

17. The gas produced in coal mines commonly called 
fire damp, which, until within a few years occasioned the 
destruction of so many lives in the mines of England, is 
light carburetted hydrogen ; this gas being inflammable 
when it is approached with a candle, takes fire and pro- 
duces violent explosions. 

18. It has been found that this gas will not inflame 
by iron wire heated red hot ; so that if a lamp be inclos- 
ed in a wire gauze of certain dimensions, it maybe made 
to subserve all the purposes of affording light to the men 
m the mines without danger of explosions. On this 
principle. Sir H. Daw's safety lamp is formed 



TO CHEMISTRY. 89 

1 9. Hydrogen unites with sulphur, phosphorus and 
carbon. It is then called sulphuretted, phosphuretted 
and carburetted hydrogen gas. 

20. Phosphuretted hydrogen gas possesses the prop- 
erty of being inflamed, when exposed to atmospheric 
air. 

Exp. Introduce into a retort a diluted solution of 
caustic potash, with a small piece of phosphorus, plunge 
the beak of the retort into water, heat the retort by 
means of a lamp until the liquor boils, bubbles will pass 
out of the retort, which, as soon as they reach the sur- 
face, will inflame. 

Observation. This is one of the most interesting ex- 
periments in chemistry. 

21. Sulphuretted hydrogen gas is produced by the 
decomposition of animal and vegetable substances. 

Observation. It is this gas which causes the fetid 
effluvia which arises from vaults and drains. It i& like- 
wise found in some mineral waters: 

22. Hydrogen united with oxygen in certain propor- 
tions, produces the most intense heat hitherto known ; 
for this purpose it has been applied in an instrument, 
called an oxy-hydrogen blow pipe* 

PRACTICAL QUESTIONS. 
What is hydrogen ? 

Does it exist in great quantities in nature ? 
What are its characteristics ? 
What other properties has it ? 
Can it be taken into the lungs I 
Wliat is its specific gravity ? 
What portion has it, in the composition of waterl 
How does it form water ? 
Is it by mixture, or chemical combination ? 



9Q STRODE CTION 

How is hydrogen obtained ? 

How do you decompose water by electricity ? 

Of what should the wires in this experiment be made ? 

How can you collect the gases separately by electrici- 

v • 

How do you decompose water by means of heat ? 

What experiment have you to shew, that water is 
formed by combustion ? 

What peculiar effect does hydrogen, in combustion- 
have on glass ? 

How do you perform this experiment ? 

How do you account for this ? 
- How is the flame of a candle or lamp produced ? 

To what is flame, in general, owing ? 

Why is it regular and tapering ? 

How do you produce a detonation with hydrogen I 

What is the gas obtained from pit coal ? 

How are gas lights produced ? 

How can you imitate the gas lights ? 

How is this gas obtained on a large scale ? 

What is fire damp ? 

On what principle is Sir H. Davy's safety lamp cob*- 
structed ? 

What is sulphuretted, phosphuretted and carburetted 
hydrogen ? 

What property does phosphuretted hydrogen gas pos- 
sess ? 

How would you illustrate this by experiment ? 

How is sulphuretted hydrogen gas produced ? 

What is the consequence of the union of oxygen and 
hydrogen ? 



TO CHEMISTRY. (Jf 



CHAP. IX 
Of Sulphur. 

1. Sulphur or brimstone is sometimes found in a state 
of purity, but more frequently mixed with other sub- 
stances ; particularly with metals. 

2. In the state of combination, the several metallic 
substances combined with sulphur, were called Pyrites ; 
by the new nomenclature, sulphurets. 

Illustration. Sulphur united with iron, forms martial 
pyrites ; united with copper, copper pyrites ; or sulphu- 
ret of iron, or copper. 

3. Sulphur also exists in vegetables, and it is emitted 
from animal substances in a state of putrefaction, com- 
bined with hydrogen, 

4. Sulphur is obtained by roasting or exposing met- 
als to heat, sufficient to drive off the sulphur which is 
condensed on the top of the furnace. 

5. The characteristics of sulphur are, it is brittle t 
electric, fusible at 220° Farenheit, burns with a pale blue 
flame at 302°, and a bright white one at 370°. 

6. Its specific gravity is 1.99 to 2.325. 

7. When sulphur is kept melted in an open vessel 
for some time, at about 300° F. it becomes thick and vis- 
cid, and if it be then poured into a bason of water, it 
appears of a red colour and ductile, like wax. 

8. The substance sold under the name of foyers of 
sulphur, is merely sulphur sublimed or minutely divided 
by means of heat. 

Exp. Place some lumps of sulphur in the cucurbit, 
such as was used for alcohol and sulphur. Plate 2, fig. 4. 
And having placed the head upon it set it in a sandbath^ 



92- mTROBrcTioic 

which must be gently heated. The sulphur soon begins 
to melt and immediately a thick white smoke rises, which 
is gradually deposited within the head, where it condens- 
es against the sides somewhat in the form of vegetation r 
whence its name. When first formed, it is of a pungent 
and offensive smell. 

9. Sulphur in combustion in close vessels, combines- 
with the oxygen within the vessel, and forms a com- 
pound totally different from sulphur in its pure state. 

Exp. Put a small quantity of the flowers of sulphur in- 
to a tea cup, and place it in a saucer filled with water, 
with a hot iron set fire to the sulphur. It burns with a 
faint bluish flame, invert over it a bell glass, white 
fumes will arise from the sulphur and fill the vessel, at 
the same time the water will rise in the receiver: the 
water absorbs the gas and acquires acid properties which, 
did not previously exist in the sulphur 

Illustration. Sulphur in the state of vapour absorbs 
the oxygen in the receiver, and assumes the form of an 
elastic fluid of a pungent and offensive smell. A chemi- 
cal combination of oxygen and sulphur takes place, and 
a true gas is formed which would continue so under the 
pressure and temperature of the atmosphere, if it did not 
combine with the water to which it imparts its acid taste 
and all its acid properties. The oxygen in this case is 
the acidifying principle. 

10. Sulphur combines with oxygen in four definite 
proportions, forming an interesting class of acids, viz. i 

The sulphurous, hypo sulphurous, sulphuric and lujpo-sul- 
phuric. From these combinations- it is inferred that the 
prime equivalent of sulphur is 2, and the density of its 
vapour is 1.111, equal to that of oxygen. 

Observation. In the last experiment the acid formed 
was the sulphurous, which is the weakest degree of acid 



70 CHEMISTRY. 93 

ification ; when fully satutrated it is the sulphuric and hy- 
posulphuric. 

Exp. Provide a large glass receiver with a glass stop- 
per at top, and having filled it with oxygen gas in the 
pneumatic cistern, slide it oil the shelf into a plate con- 
taining water, then introdnce a piece of sulphur into the 
receiver through the opening at the top and with it a 
small piece of lighted tinder. It burns with a very bril- 
liant blue light, and quickly fills the receiver with va- 
pour, which is condensed in the water below and forms 
sulphuric acid diluted, which may be condensed by evap- 
oration. 

11. Sulphur has hitherto been considered as a sim- 
ple substance, but recent experiments seem to shew that 
it is combined with a small portion of hydrogen and 
perhaps of oxygen. 

Illustration. Sir H. Davy observed^ on submitting sul- 
phur to the action of the voltaic battery, that the negative 
wire gave out hydrogen ; and by the combustion of sul- 
phury small quantity of water was produced which indi- 
cated the presence of hydrogen. 

12. Sulphur combines with the metals, earths and al- 
kalies, forming hard substances called Sulphurets. 

Exp. 1. Heat an iron bar red hot, and apply to it a 
roll of sulphur, the latter becomes melted, and the drops 
that fall will be found to be a sulphuret of iron.. 

2. Boil muriate of ammonia, lime and sulphur togeth- 
er, the compound will be soluble in water. 

1 3. Oil of turpentine, and other essential oils, dissolve 
a considerable proportion of sulphur when hot, the great 
est part of which is deposited in crystals when cooled 
slowly. 

14. The fat oils unite with sulphur by boiling,, and 
acquire a deep yellowish brown colour ; and a strong 
fetid odour. 



94 INTRODUCTION 

1 5. Sulphur combines with chlorine forming a peculiar 
compound called chloride of sulphur, having the follow- 
ing characteristics. It is a fluid appearing red by reflec- 
ted, and yellowish green by transmited light, Specific 
gravity 1. 7. In the air it fumes and emits a pecu- 
liar odour somewhat resembling sea weeds. Its taste is 
acrid, hot, acid and bitter. Water decomposes it, the 
sulphur is precipitated, and the liquor is found to contain 
sulphuric and muriatic acids. 

When added to nitric acid a mutual decomposition takes 
place with violence, nitric oxide gas and chlorine are 
evolved and sulphuric acid is formed., 

Exp. This may be formed in the following manner. 
Pass a current of chlorine over flowers of sulphur, or 
having filled a retort with chlorine gas or oxymuriatic 
acid gas, heat flowers of sulphur in it until they sub^ 
lime. 

16. Sulphur unites with cyanogen, or prussine, form- 
ing a substance called sulpho-cyanic acid by some, by 
others sulphuretted chyazic acid. 

17. The characteristics of this substance are. It is 
a colourless and transparent fluid, specific gravity 1 .022, of 
a pungent smell like strong acetic acid. It combines 
with saleiiable bases, and forms salts called sulpho-cyana- 
tes. They are soluble, deliquescent and crystallizable. 
According to Dr. Thomson, it is composed of 1 atom cy- 
anogen and 3 atoms sulphur^ 

Exp. The following method has been adopted to ob- 
tain it. Three or four parts of prussian blue added in 
small quantities at a time, are boiled in a solution of one 
part of sulphuret of potash in water; a transparent, col-, 
ourless and neutral liquid is obtained, to which after be- 
iag filtered, sulphuric acid must be added, in sufficient 
quantities to give it; decidedly acid properties, The.^ 



1*0 CHEMISTRY. #6 

-liquid is Itept for a short time at a temperature near a 
boiling point, and afterwards allowed to cool. On the 
addition of a little finely pulverized oxide ofmangane.se, 
the solution acquires a fine crimson colour, and after ni- 
tration it is decomposed by pouring into it two parts of 
sulphate of copper, and three parts sulphate of iron in 
water, until the crimson colour disappears, a white pre- 
cipitate, composed of sulpho cyanic acid, and oxide of 
copper is formed ; the former of which is transferred to 
potash when boiled in the solution. To the filtered li- 
quid is added sulphuric acid in excess, and by subsequent 
distillation the sulpho-cyanic acid passes over into the 
receiver, mixed with a little sulphur and sulphuric acid, 
from which it may be freed by saturating the liquid with 
carbonate of bary tes, 

18. Sulphur unites with phosphorus, and when com- 
bined may be made to contain various proportions of itg 
elements, and exhihit different phenomena. The com- 
pounds are exceedingly inflammable and more fusible 
than either of their elements. 

Exp. 1 proportion of phosphorus and 3 of sulphur, 
congeal at 100° F. 2 of phosphorus and 1.5 of sulphur 
remain liquid at 40° 4 and 8 of phosphorus and 1 of sul- 
phur at 68° F. 

19. Sulphur combines with carbon forming a com- 
pound long known by the name of alcohol of sulphur, 
possessing the following properties. Its taste pungent 
and disagreeable ; smell stronger than sulphuretted hy- 
drogen. It boils at the temperature of 110 to 115°. The 
elasticity of its vapour at 55° is such as to support 7.25 
inches of mercury. Water at the same temperature 
supports 4.3 ; alcohol 1.23, and ether 1 1 inches. By evap- 
oration it produces a greater degree of cold than ether. 
It may be cooled down to 50° without freezing ; itreadi- 



$0 INTRODUCTION 

ly dissolves sulphur, but if to the solution be added 'ether 
or alcohol, the excess of sulphur is precipitated, and the 
two liquids combine. 

Exp. ft may be obtained by subliming sulphur through 
ignited charcoal in a porcelain tube. The first product 
is a liquid of a yellowish colour, which colour is owing 
to the presence of a little sulphur. By distillation in a 
glass retort, a colourless product is obtained which is the 
pure sulphuret of carbon, 

20. Sulphur is applied to many important uses. It 
Is employed in medicine, it enters into the composition of 
sulphuric acid, of gun powder, and of the common com- 
position for paying the bottom of ships. Its fumes are 
employed in bleaching of silk and wool, and checking the 
progress of yinous fermentation. Common matches, for 
lighting fires are tipped with sulphur. 

PRACTICAL QUESTIONS. 

In what state is sulphur found ? 

What is the mineral combination called ? 

Does sulphur exist in any other substance but mine- 
rals ? 

How is sulphur obtained ? 

What are the characteristics of sulphur ? 

What is its specific gravity ? 

What is the effect when sulphur is kept melted for 
.some time in an open vessel ? 

What are flowers of sulphur ? 

Illustrate this by experiment, 

When sulphur combines with oxygen in combustion^ 
what is the compound? 

What experiment illustrates this ? 

Explain the process 



YO CHEMISTRY, 07 

Mow many proportions of oxygen is sulphur capable 
of combining ? 

How would you form sulphuric acid ? 

Is sulphur a simple substance ? 

How is this proved? 

With what does sulphur combine ? 

Illustrate this by experiment. 

Can sulphur be dissolved in essential oils ? 

What effect do fat oils produce on sulphur ? 

What is chloride of sulphur 1 

How do you form it ? 

What is sulpho-cyanic acid ? 

Relate the method for procuring it 

What is sulphuretted phosphorus ? 

What phenomena do the different proportions of sul- 
phur exhibit ? 

What are the characteristics of sulphuretted carbon % 

How can it be obtained ? 

What are the uses of sulphur ? 



CHAP. X. 
Of Phosphorus. 

1. Phosphorus is a substance which exists in many 
animal and some vegetable substances, and may be ob- 
tained by decomposing the bones of animals 

2. It is never found in its simple state, but always in 
combination, from which it cannot be separated but by a 
chemical process. 

3. Its characteristics are. It is semi-transparent, solid, 
slightly brilliant, and of the consistence of wax* Specific 

9 



08 INTRODUCTION 

gravity 1.77. Taste somewhat acrid and disagreeable, 
smell resembling in some measure garlic. 

4. It is brittle under 32°, fracture vitreous, brilliant 
and sometimes lamellated. 

5. Above 32°, it softens a little, at 90° it becomes 
ductile, melts at 99°, becoming transparent like a white 
&A at 180° begins to be vaporized, and boils at 550. 

6. It is highly inflammable, when heated in the air it 
takes fire at the temperature of 148° and burns with a 
very bright flame, emitting a large quantity of vapour or 
smoke. 

Exp. 1. If a small bit of phosphorus be put upon the 
outside of a Florence flask, and hot water be put into the 
flask, the phosphorus will immediately take fire and ex- 
hibit a beautiful appearance. 

Exp. 2. Put 30 grains of phosphorus into a Florence 
flask with four ounces of water; cause the liquor to boil 
over a lamp, balls of fire will soon be seen to issue 
through the water, after the manner of an artificial fire 
work, attended with the most beautiful corruscations. 

Exp. 3. R,ub cotton in pulverized rosin, and wrap it 
round a small piece of phosphorus, then place the whole 
under the receiver of an air pump, after exhausting the 
receiver, the cotton will take fire and display a very 
beautiful appearance on the admission of the air. 

Exp. 4. Take a bit of phosphorus about the bigness 
of a large pars head, and having wiped it upon blotting 
paper, put it into the middle of a piece of dry cotton, strike 
it with a hammer and it will inflame. 

7. Phosphorus in combustion in oxygen gas, absorbs 
it and consumes nearly once and a half its own weight, 
and phosphoric acid is produced equal in weight to the 
-oxygen and phosphorus consumed. 

Exp. 1 . Attach a bit of phosphorus to a small spoon 
and plunge it into a receiver containing oxygen gas ; it 



TO CHEMISTRY. 99 

produces the most brilliant white light imaginable . 
concrete white flakes adhere to the sides of the receiver 
which will be found to be phosphoric acid. 

8. Its combustion in oxygen gas furnishes results 
different from all other combinations, viz. phosphoric and 
phosphorous acids or oxide of phosphorus. 

Exp. Into a retort that will hold about a pint, put half 
a pint of water, and then add a small bit of phosphorus, 
place it over a lamp and when it gets warm, stars of fire 
resembling sky rockets will be seen shooting about the 
water in a most beautiful manner, and adhering to the 
sides of the retort. If the lamp is withdrawn when the 
water boils, a curious appearance resembling the aurora 
borealis,,is seen at the surface of the water. If the heat 
be continued, a stream of light is seen to issue from the 
mouth of the retort, which returns into the retort when 
taken away.. 

9. Phosphorus combines with oxygen at a lower 
temperature than most other substances, whence ti m 
great attractive power for this principle ; hence the facil- 
ity with which it takes fire. 

Exp. Put a piece of phosphorus into a quill and write 
with it on the wall of a dark room ; the words thus writ- 
ten will appear as if brilliantly illuminated. It is by slow 
combustion, in consequence of the rapid absorption of 
©xygen, that the light is produced. 

10. In open air phosphorus undergoes a slow combus- 
tion at 43° emitting light in the dark without the produc- 
tion of sensible heat, absorbing a portion of oxygen and 
producing phosphorous acid, 

Exp. Provide a glass funnel, place it in the mouth of 
a bottle, then take sticks of phosphorus enclosed in glass 
tubes to prevent their contact, and place them round the 
inside of the funnel Put a little -distilled water into the. 



100 INTRODUCTION 

receiver and suffer the apparatus thus arranged to re* 
main 24 hours, a quantity of phosphorous acid will be 
formed. 

Observation. It may at first appear singular that phos- 
phorus should burn at so low a temperature in atmos- 
pheric air, when heat must be applied for its combustion, 
in oxygen gas But this circumstance seems to be owing 
to the nitrogen gas of the atmosphere. This gas dis* 
solves small particles of phosphorus, when in contact 
with it, which being thus minutely divided and diffused 
in the atmospheric air, combines with the oxygen and 
undergoes a slow combustion. The reason why the 
same effect does not take place in oxygen gas is, that 
oxygen is not capable of dissolving phosphorus. It is 
therefore necessary that heat should be applied to effect 
that division of the particles which in the last case is 
effected by nitrogen. 

11. Phosphorus combines with 6ulphur and forms~a 
compound, which takes fire in contact with atmospheric 
air. 

Observation. It is this composition which forms what 
is called phosphoric matches. 

Exp. Mix one part of flowers of sulphur with eight 
parts of phosphorus, and dip a splinter of pine wood into 
the mixture. Rub the end against a piece of cork or 
wood, and a flame will be immediately produced. 

12. Phosphorus is soluble in fixed, essential oils, and 
ether. 

Exp. 1. Dissolve some phosphorus in sulphuric ether, 
this solution when poured in small quantities into hat 
writer exhibits a beautiful appearance. 

13. At the temperature of 70° F. phosphorus com- 
bines with oil, and forms a compound, which in contact 
with atmospheric air becomes luminous in the dark. 



TO CHEMISTRY, 101 

Exp. Fiit one part of phosphorus into six part3 of good 1 
olive oil, or oil of cinnamon, which is preferable. Di- 
gest it in a gentle sand heat until the phosphorus is dis- 
solved, on which, immediately cork the bottle. If this 
oil be rubbed on any thing, it becomes luminous in the 
dark, and yet has not sufficient heat to burn the sub- 
stance. 

14. Phosphorus combines with lime and forms a cook 
pound which has the singular property of decomposing 
water, by being thrown into it ; which is owing to its 
absorbing oxygen from the water ; called phosphuret of 
lime. 

Exp. Put half an ounce of phosphorus cut small into 
a glass tube about a foot in length, and half an inch in 
diameter, closed at one end and filled up with quicklime 
grossly pulverized, stop the tube loosely. Heat that 
part of the tube which contains the lime until it becomes, 
red hot, and then apply the heat of a lamp to the part 
containing the phosphorus, which will sublime and mix 
with the lime. When thrown into water, a decomposi- 
tion takes place, phosphuretted hydrogen gas is evolved, 
and rises in bubbles to the surface where it immediately 
inflames. 

15. Phosphorus combines with many of the metals 
and forms peculiar compounds ; with iron it forms what 
Smiths' call cold short 

16. Phosphorus is usually obtained from the phos- 
phoric acid which exists in the bones of animals. 

Exp. Calcine bones to whiteness in an open fire, and 
having pulverized them, put them into a stone ware pot 
pour gradually upon the powder diluted sulphuric acid, 
continually stirring the mixture, until it is reduced to 
the consistence of cream, after the powder has subsided^ 
9* 



102 INTRODUCTION 

pour off the clear liquor, reserving it, and add water T 
pour this to the former liquor, and throw the sediment 
on a # filtre, then add hot water until it passes through the 
filtre, tasteless. This fluid must be gradually evaporated 
in a glass vessel to the consistence of syrup. It is then 
mixed with an equal weight of charcoal powder and sub- 
mitted to distillation in an iron or earthen retort. Instead 
of a receiver, the neck of the retort should be immersed 
in a vessel of water to a small depth, and the phosphorus 
as it comes over, will fall in drops to the bottom. It may 
be purified by a second distillation. 

PRACTICAL QUESTIONS, 

What is phosphorus ? 

Is it ever found in its simple state ? 

What are its characteristics ? 

What is its state under 32° of temperature ? 

What is it above 32°. 

What is its appearance at the temperature of 99° 2 

Illustrate this by an example. 

What are the phenomena of the combustion of phos- 
phorus in oxygen gas ? ( 

W^hat are the results of the combustion ? 

At what temperature does phosphorus combine with 
oxygen ? 

What does phosphorus undergo in the open air ? 

How do you form phosphorous acid ? 

How do you explain the cause, that phosphorus in- 
flames spontaneously in atmospheric air, and not in oxy- 
gen gas ? 

What is the compound of phosphorus with sulphur ? 

Is phosphorus soluble in oils ? 



TO CHEMISTRY. 103 

At what temperature does phosphorus combine with 
oil, and what is the compound ? 
What is phosphuret of lime ? 
How do you prepare it ? 
Does phosphorus combine with metals ?_ 
How is phosphorus prepared ? 



CHAP. XL 

Of Carbon. 

1. Carbon is the base of the carbonic acid: in its 
greatest state of purity; it exists only in the diamond, 

2. Charcoal in a state of purity, that is, unmixed with 
any foreign substance, is carbon. 

3. Carbon forms a considerable portion of the solid 
matter of all organized bodies ; but it is most abundant in 
the vegetable creation,, and it is principally obtained from 
wood. It is prepared by charring or burning in close 
vessels wood, which, when deprived of the water and 
oil, is charcoal. 

Exp. t. Expose wood of any kind, stripped of it& 
bark, to a red heat in a close vessel, till vapours cease 
to issue ; a black, opaque, shining, brittle substance will 
be obtained, which is charcoal. Pulverize this substance, 
and digest it in diluted muriatic acid, and afterwards ap- 
ply repeated affusions of cold water and then dry ; it in a 
heat approaching to redness, it may be obtained suffi- 
ciently pure for general purposes. Common charcoal 
dried in the above heat, will answer for common pui> 
poses. 



!04 INTRODUCTION 

4. The characteristics of good charcoal are. It is 
fixed in the fire, no heat being able to volatilize any con- 
siderable portion of it. It forcibly attracts and strongly 
retains a small quantity of water.* Its antiseptic qualities 
are very great, and for this purpose it is used in purify- 
ing and cleansing many foul and fetid substances. 

Illustration 1. It is employed in correcting the bad 
smell of corrupted water, of oiled silk bags, of ill condi- 
tioned ulcers, and for cleansing the teeth. 

2. An excellent dentifrice may be prepared by pul- 
verizing together in a common mortar, a piece of char- 
coal, a lump of chalk, and a bit of gum-mirrh, and sifting 
it through muslin. 

Exp. Throw a quantity of well prepared charcoal in 
powder into water, which has been long kept, or which 
has become foul by being in contact with putrid sub- 
stances, and the water will become perfectly sweet in 
the course of a few hours. 

Illustration 1 . The properties of charcoal in resisting 
putrifaction, have suggested its application to casks con- 
taining water during long voyages. The inner surface 
of the casks should be charred, when they are manufac- 
tured. 

2. Piles or stakes driven into the ground, will last 
much longer, if they be charred in the same manner. 

5. The most perfect carbon that can be prepared by 
art, contains about five per cent of hydrogen. 

6. Well burnt charcoal is a conductor of electricity, 
though wood simply deprived of moisture by baking, is a 
non-conductor; but it is a very bad conductor of caloric. 

Observation. Sir H. Davy is of opinion, that if we 
could obtain carbon free from foreign ingredients, it 
would be metallic, in common with other, metallic sub^ 
stances. 



TO CHEMISTRY. I0U. 

7. Diamond is carbon in a crystallized state ; but we 
are ignorant of the means which nature employs to crysr 
tallize it. 

8. Diamond is combustible, and it is in consequence 
of this property, that its chemical nature has been ascer- 
tained. 

Illustration. Apply a degree of heat excited by the 
blow pipe and a stream of oxygen gas, the product will 
be pure carbonic acid. 

Exp. Charcoal will answer instead of diamond. Pro- 
cure some oxygen gas, having made the charcoal red 
hot, place it on a dish and introduce it into the jar. It 
will burn with great brilliancy. When combustion ceasr 
es, pour into the glass a small portion of tincture of lit- 
mus, and it will be converted to a red, intimating the 
formation of an acid during the combustion of the char- 
coal. If newly made lime w r ater be poured into the jar, 
a pellicle will immediately form on the surface of the 
water, which is a proof that the jar contains carbonic 
acid. 

9. Carbonic acid is not a condensible vapour, but a 
permanently elastic fluid, which always remains in the 
state of gas under any temperature and pressure ; it was 
formerly called fixed air, 

10. Less light and heat are given out during the com- 
bustion of carbon in oxygen gas, than in that of most 
other substances ; because the oxygen, instead of enter- 
ing into a solid or liquid combination, is employed in 
forming another elastic fluid ; it therefore parts with 
less caloric. 

11. If we take into consideration the quantity of oxy- 
gen that carbon absorbs during combustion, and observe 
the proportion which the caloric bears to it, we may as- 
certain the degree of solidity ia which oxygen is com- 
bined with it t 



106 INTRODUCTION 

12. Carbonic acid has a great tendency to combine 
with other substances ; the compounds are called carbo- 
nates. It is also combined with water. 

Illustration. It is this product which gives the agreea- 
ble zest to beverages, which are the results of fermen- 
tation ; bottled cider and beer, and champaign owe their 
grateful taste to the diffusion of carbonic acid. It con- 
tains all the antiseptic properties of its base, carbon ; 
hence the great importance of it in putrid diseases. 

13. Carbonic acid united with lime, forms chalk, mar- 
ble, and most of the stones used in making lime. 

14. It is nearly twice as heavy, bulk for bulk, as at- 
mospheric air ; and where it exists in the atmosphere^ 
occupies a space nearest the surface of the earth. 

Illustration. Hence the reason, why dogs and other 
small animals are suffocated in caves, containing this gas> 
while man may walk upright with impunity. 

Exp. Balance a large funnel of paper in a pair of 
scales, and pour carbonic acid into it from a spout of a 
jar, when that end of the balance will descend ; this, 
shews that it is heavier than atmospheric air. 

15. Carbonic acid does not support respiration nor- 
combustion. 

Exp. 1. Fill a jar with carbonic acid gas, and put into 
it a mouse, the animal will be instantly suffocated. 

2. Pour the gas from a bottle on a lighted candle, it 
will be instantly extinguished, as though water had been 
poured upon it. 

16. When plants are made to grow in carbonic acid 
gas, they absorb the base of the acid, a decomposition 
takes place, and pure oxygen is evolved. 

17. Carbonic acid gas precipitates lime combined 
with water, and is an excellent test to discover the pre- 
sence of lime in that fluid, 



TO CHEMISTRY. 107 

Exp, Having prepared some lime water, breath into 
it from a pipe, and a pellicle will immediately be form- 
ed on the surface of the water, which is, carbonate of 
lime. 

18. Carbon may be converted into a gas by uniting 
with a smaller proportion of oxygen than is sufficient to 
form the carbonic acid gas ; it is called carbonic oxide, 
or gaseous oxide of carbon. 

19. Carbon is capable of decomposing water, when 
heated to redness, it then separates oxygen from hydro- 
gen. 

Illustration. A small quantity of water thrown on a 
red hot fire will increase the heat ; for the coals or 
wood decompose the water, and thus supply the fire> 
both with oxygen and hydrogen gases. 

Exp. Substitute a porcelain tube, containing charcoal, 
in place of the gun barrel, plate 3, fig. 1 . A lamp being 
placed under the retort, containing water, is caused to 
boil, the vapour is gradually conveyed through the red 
hot charcoal, by which it is decomposed, and the hydro- 
gen gas which results from the decomposition, is collect- 
ed in the receiver. This gas is not pure hj'drogen, but 
is combined with a small portion of carbonic acid, which 
gives it peculiar properties ; it is known by the name of 
carbonated hydrogen gas. It obtains the carbonic acid 
from the union of the oxygen with the carbon. 

20. Carbon is frequently combined with hydrogen in 
a state of solidity, as in coals, which owe their combusti- 
bility to those two principles. 

Illustration. The flame of coals is produced in conse* 
quence of the carburetted hydrogen which they contain; 
when this gas is consumed, the carbon continues to burn 
without fiame 



tOU INTRODUCTION 

21. Carbon is a non-conductor of heat ; charcoal is 
therefore used in the construction of refrigerators, for 
keeping liquors and other substances cool in warm weath- 
er, and likewise for coating furnaces and other chemical 
apparatus. 

22. Plumbago, commonly called black lead, is a com- 
bination of iron with carbon, and contains about five per 
cent of iron. This substance is called carburet of iron, 
and approaches as near the diamond as any other sub- 
stance known. 

23. Steel is a combination of iron with carbon ; the 
combination of carbon varies in different species, in all 
it is very small, amounting from 180 to 140 parts by 
weight. 

21. The essential constituent principles of oils and 
fat, both vegetable and animal, are carbon and hydrogen ; 
the difference of their appearance arises from the differ- 
ent proportions of these substances, and from other in- 
gredients, that are not chemically combined with them. 

25. The difference of fixed oils and essential, or volatile 
oils, consists in the various proportions of carbon and hy- 
drogen. The essential oils contain nearer proportions 
of carbon and hydrogen, and are volatilized or evapor at- 
ed without being decomposed ; whereas fixed oils cannot 
be without a decomposition. 

26. The facility with which oil burns is owing to the 
combustibility of its constituents. 

27. The difference between wax and tallow is prin- 
cipally owing to the degree of the purity of the com- 
pound ; both have the same essential ingredients ; but 
tallow contains animal matter. 

28. The combustion of a candle and lamp, both pro" 
duce carbonic acid gas and water. 



TO CHEMISTRY, 109 

Illustration. In this case, the fixed oil is decomposed 
&9 the combustion proceeds, the carbon unites with a por- 
tion of oxygen from the atmosphere, and carbonic acid 
gas is formed ; whilst the hydrogen combines with anoth- 
er portion of oxygen, and water is produced. 

29. Carbon and hydrogen acidified by oxygen, form 
the constituents of all vegetable acids ; likewise gum, 
starch, sugar are composed of these ingredients, and are 
called by some chemists, vegetable oxides. 

30. In chemical operations, carbon is of essential ser- 
vice, by combining with the oxygen, from the very great 
affinity which it has for that substance. 

Illustration. Many of the metallic oxides are deoxy- 
genated, or restored to their metallic state, by mixing 
them with charcoal. 

Exp. Take red lead, tritoxide, which is lead in the 
third state of oxidizement, and mix it with a quantity of 
powdered charcoal in a crucible ; subject it to heat in a 
furnace for about an hour, then suffer it to cool, and a 
small button of metallic lead will be found at the bottom 
of the crucible. 

PRACTICAL QUESTIONS, 
What is carbon ? 
What is charcoal ? 

How is carbon or charcoal obtained ? 
What are the characteristics of good charcoal ? 
How do you illustrate this ? 

What does the most perfect carbon, that can be pre- 
pared, contain ? 

Is charcoal a conductor of electricity ? 

What is Sir H. Davy's opinion on this subject ? 

What is diamond ? 

How has its chemical nature been ascertained ? 



110 rNTRODUCTION 

Illustrate this by experiment. 

What is carbonic acid ? 

Why is it that less light and heat are given out during 
the combustion of carbon in oxygen gas, than that of any 
©ther substance ? 

How can we ascertain the degree of solidity in which 
oxygen is combined with carbon, during combustion ? 

What are carbonates ? 

What gives the agreeable zest to beverages ? 

What is chalk and marble ? 

How heavy is carbonic acid gas ? 

What is the reason that small animals are suffocated in 
caves ? 

Does carbonic acid gas support combustion and respi- 
ration ? 

Illustrate it by experimentc 

What effect do growing plants have on carbonic acid ? 

W T hat effect does it have on lime water ? 

Illustrate it by experiment. 

What is carbonic oxide ? 

Can water be decomposed with carbon ? 

In what manner ? 

What is the gas formed ? 

Can carbon be combined with hydrogen in a state of 
solidity ? 

Illustrate it. 

Why is charcoal used in refrigerators, and in coating 
furnaces ? 

Wliat is plumbago ? 

What is steel ? 

What are the constituents of oil and fat ? 

What causes the difference in their consistence ? 

What causes the difference between fixed and essential 
©Ife 9 



TO CHEMISTRY. Ill 

To what is the facility with which oil burns owing ? 

To what is the difference between wax and tallow ow- 
ing ? 

What does the combustion of a candle and lamp pro- 
duce ? 

Illustrate this. 

What forms the constituents of all vegetable acids ? 

What are vegetable oxides ? 

What use is carbon in chemical operations ? 

Illustrate this, 



CHAP. XII. 

Of Alkalies. 

l: Alkalies are a class of bodies distinguished by th« 
following properties. They impress the tongue with a 
peculiar acid taste, which has been termed caustic or 
urinous ; a sensation commonly considered as contrary to 
sour. They have a strong affinity for water, with which 
they combine with great rapidity, and in great quantity. 
They change blue vegetable colours to green, the brown 
to yellow, and the yellow to orange. They corrode and 
dissolve animal substances. They unite with the oils and 
fats, and form compounds called soaps. They combine 
with many chemical agents, particularly the acids ; with 
which they form the neutral salts. They are capable of 
being fused and volatilized by heat. 

Observation. Some of the above properties are dis- 
covered in two or three of the earths ; barytes and stron- 
tian have been considered as alkalies by Vauquelin and 
Fourcroy, and some other French chemists. But this 



1 1 2 INTRODUCTION 

arrangement has not been very generally received ; be* 
cause, as has been observed, if we admit these amongst 
the alkalies, there is hardly any good reason for exclud- 
ing lime, magnesia, and some other of the earthy sub- 
stances ; and because the greater solubility and fusibility 
of the alkalies sufficiently distinguish them from all these 
substances, which have also properties common to them- 
selves. 

2. The cause of alkalies being caustic, is the strong 
affinity which they possess for the constituents of animal 
matter. In their pure state, they have a powerful at- 
traction for water, hydrogen and carbon, which are the 
constituent principles of oil, and it is principally by ab- 
sorbing these substances from animal matter, that they 
effect its decomposition ; for when diluted with a suffi- 
cient quantity oi water, they lose their causticity. 

Illustration. Caustic potash in solution is unfit for 
washing, but when incorporated with oil, it forms the 
well known substance called soap, which is universally 
used as a mild and excellent cleanser of the hands and 
face. 

3. Whenever acids are in contact with alkalies or al- 
kaline earths, they unite with avidity and form compounds 
totally different in their properties from either ©f the 
constituents ; these bodies are called neutral or compound 
salts. 

Exp. To aqua fortis add carbonate of ammonia, (sal 
volatile) to the point of saturation; that is, until all effer- 
vescence ceases, or until fixed air ceases to be disengag- 
ed ; the acid loses its acidity, and the ammonia its pun. 
gency. 

4. The alkalies are divided into two kind?, fixed and 
tolatik. 



TO CHEMISTRY. 1 13 

5. The fixed are those which do not evaporate on 
exposure to the air ; these are potash, soda and lithia. 

Note. — There are a number of newly discovered vege* 
table alkalies, which will be treated of in the vegetable 
department 

6. The volatile alkali evaporates on exposure to the 
air, in the form of gas ; this is ammonia. It contains no 
oxygen. 

7. Potash derived its name from the pots, in which 
the vegetables from which it is obtained, used formerly to 
be burnt ; the alkali remained mixed with ashes at the 
bottom, and was thence called potash. 

8. It exists in nature in a great variety of forms and 
combinations, but is never ftmnd in a state of purity ; it 
is combined with carbonic acid, with which it exists in 
every part of the vegetable kingdom,, and is most com- 
monly obtained from the ashes of vegetables, which is 
the residue when all the other parts are volatilized by 
combustion. 

9o* Potash is obtained in the arts from wood ashes by 
lixiviation and evaporation. 

10. Potash, as prepared in the manufactory, contains 
water, which is not easily separated by heat; 100 parts 
usually contain about 17 parts of water. It may, there- 
fore, properly be called an hydrate of potash. 

11.- Potash deliquesces or becomes liquid in the air, 
in consequence of its strong affinity for aqueous vapour. 

12. It dissolves in one half its weight of water at 58° v 
and during the solution, heat is evolved. 

Exp. Take a small quantity of potash in a phial, and 
holding it in one hand, add to it a little water, as the so- 
lution goes on, a sensible warmth is communicated to the 
band, 

10* 



114 INTRODUCTION 

Illustration. This phenomenon may probably be ac- 
counted for, by supposing that a solution of potash in wa- 
ter has a less capacity for heat than either of them in a 
separate state. 

13. The specific gravity of pure potash, 1.7. 

14. A perfectly pure solution of potash will remain 
transparent, on the addition of lime water ; shew no ef- 
fervescence with dilute sulphuric acid, and do not give 
any precipitate on blowing air from the lungs through 
it by means of a tube. 

15. Potash in its caustic state is often used by sur- 
geons, under the name of potential cautery , to open ab- 
cesses and destroy excrescences. And it was formerly us- 
ed in medicine, diluted with broths, in cases of stone 
and gravel. 

16. In an intense heat, it becomes greenish and may 
be vaporized, but is perfectly incombustible. 

17. It may be crystallized into long compressed, 
quadrangular prisms, truncated by sharp pyramids. 

18. It combines with carbonic acid, forming a sub- 
stance called pearl ash, in commerce ; and when purifi- 
ed, salt of tartar. 

Exp. Heat common potash to redness in a reverbe- 
rating furnace, many of the impurities will be driven off, 
and it becomes much whiter than before ; when cool, it 
will be found to contain carbonic acid, and is properly a 
sub carbonaio of potash, or potash not fully saturated 
with carbonic acid. 

19. Potash is sometimes employed to produce a frig- 
ovific mixture, or artificial cold. 

Exp. Mix quickly four parts of caustic potash in 
powder, fluid one of fine light snow in flakes, it will be- 
come liquid, and in the act of liquefying, a large quantity 
of caloric is absorbed ; of course, cold is produced. 



TO CHEMISTRY. 1 1 j£ 

20. Potash converts all animal matter into a sapona- 
ceous jelly, in consequence of its attraction for water 
and oil. 

Exp. Take caustic potash and olive oil, of each equal 
parts, having dissolved the potash in its own weight of 
water, add the oil and agitate it for a few moments, a 
saponaceous compound will be formed, which is per- 
fectly miscible with water. 

21. Potash fused with silex, forms glass ; silex is com- 
posed of sand and flint, it is infusible by itself, but when 
mixed with potash, it melts, when exposed to the heat 
of a furnace, combines with the alkali and runs into 
glass, which differs in its properties according to the 
proportions used, the quality of the ingredients and the 
manner of conducting the process. 

Exp. Fuse three or four parts of potash with one 
part of silex in a crucible, the result will be a soft brittle 
kind of glass, which is soluble in water ; this solution is 
called siliceous potash, or liquor of flints. 

22. Potash readily unites with sulphur, and forms the 
compound called sulphuret of potash, formerly liver of 
sulphur. 

Exp. Melt two parts of potash and one of sulphur to- 
gether, in a crucible, a liver brown substance will be ob- 
tained. 

23. Potash is obtained not only from vegetables, but 
it is found on the surface of the earth, mixed with vari- 
ous minerals, especially with earths and stones, whence 
it is supposed to be conveyed into the vegetables by the 
roots of the plants. It is also met with, though in very 
small quantities, in some animal substances. 

24. Potash changes the colour of blue vegetable in- 
fusions to a green. 



116 INTRODUCTION 

Exp. Put into a wine glass a small quantity of tincture 
of red cabbage, which is of a blue colour, add to it a few 
drops of the solution of caustic potash, and a dark sea 
green colour will be produced. 

25* Potash combines with all the acids, some of 
which are of essential service in the arts, such as its 
combination with nitric acid, called salt petre ; with oxy- 
muriatic acid, ^c. It likewise combines with phospho- 
rus, sulphuretted hydrogen, and earths ; it is used as a 
reagent in analysis, and it is the basis of all soft soaps, 

26. Potash may be considered as the hydrated deut- 
oxide of potassium. 

OF SODA. 

27. Soda is the basis of sea salt, or that used for ci> 
linary purposes, which is muriate of soda. 

28. Soda has been known by the name of mineral at- 
kali, and is found in various parts of the earth ; in min- 
erals, sea water, and many lakes and springs. When 
thus found, it is called natron. 

29. Soda may be obtained from common salt, but the 
best and usual way of obtaining it in Europe is by the 
combustion of marine plants, from the ashes of which it 
is produced in a manner similar to that for potash. It is 
likewise obtained by the decomposition of sulphate of 
soda. 

30. It derives its name from a plant called sal sola 
soda ; by the Arabians, kali, the ashes of which affords it 
in great abundance. 

31. Soda in taste, action on vegetable colours, oils and 
animal matter, resembles potash, but its specific gravity 
is not so great. 

32. When exposed to heat, it melts below ignition, 
and in the state of an hydrate, has the appearance of 
effervescence. 



TO CHEMISTRY. 117 

33. It is a non conductor of electricity. 

34. Soda has so great an affinity for water that it 
cannot be obtained free from it but at a very high tem- 
perature, what is commonly called pure soda contains 23 
per cent of water. 

Exp. To prepare pure soda, proceed as follows. Dis- 
solve any quantity of carbonate of soda in twice its weight 
of boiling water, and add to the solution while hot, an 
equal weight of quicklime, mixed with water to a thin 
paste. Boil the mixture in an iron vessel, adding as 
much water as is necessary to reduce the mass to the 
consistence of cream; boil and stir it for one hour. 
Then separate the liquid alkali either hy filtration or 
subsidence, and boil it to dryness in a silver dish. Pour on 
the dry K528 as much pure alcohol as is necessary to 
dissolve it. Put the solution into a phial until the insol- 
uble part has subsided, then decant the clear liquor and 
distil off the alcohol. Evaporate what remains in the 
retort to dryness, fuse it in a silver crucible, and pour 
it into a silver dish. When cool, break the mass into 
small pieces and preserve them in a phial closely stop- 
ped. 

35. Soda thus prepared will be ©f a greenish white 
eolour, of a urinous taste and great causticity, acting 
with great violence on animal matter. Water when 
thrown upon it is absorbed with great violence, and much 
heat is evolved accompanied with an alkaline smell. 

36. Potash and soda are used for the same purposes 
in the arts, such as in the manufacture of glass, soaps, &c. 

OF LITHION OR LITHIA. 

37. Lithia is a substance discovered in 1818, in some 
minerals in Sweden, and has been classed with the fixed 
alkalies. 



1 18 ^ INTRODUCTION 

Observation. It was first discovered in the mineral called • 
Petalite, in the proportion of 3 per cent, afterwards in the 
Lepidolite, in the proportion of about 4 per cent; and 
in the Triphane or Spodomene, in the proportion of 8 per 
cent. 

38. It is readily obtained by fusing the mineral with 
potash, dissolving the whole in muriatic acid evapora- 
ting to dryness, and digesting in alcohol. The muriate 
of lithia being soluble, is taken up while the other salts re- 
main, and by a second evaporation and solution it will be 
procured in a pure state. 

39. Lithia differs from potash and soda. 1. By the 
fusibility of its salts, 2. By the great deliquescent prop- 
erty of its chloride, or the compound of lithia and chlo* 
rine. 3. By the comparative insolubility of its carbo- 
nate. 4. By its great capacity for acids, by which it sur- 
passes Eaajaesia. . 

40. Ikthia is found to contain a metallic base analo- 
gous to potassium and sodium, and may be obtained in the 
same manner. This has been called Lithium. 

41. Lithia unites with sulphur. Sulphuret of Lithia 
has a yellow colour, dissolves readily in water, and is de- 
composed by acids in the same way as the other alkaline 
sulphurets. 

42. Phosphorus decomposes water with the help of 
oaustic lithia. 

Exp. Heat in a retort, phosphorus, with a solution of 
caustic lithia in water, phosphuretted hydrogen gas is 
disengaged which takes fire when it comes in contact 
with the air. 

43. Lithia dissolves only in small quantities in alco- 
hol of specific gravity 0.85. When weak alcohol is ad- 
ded to an aqueous solution of lithia in a well stopped 
phial, no change takes place at first, but after some 



TO CHEMISTRY . 1 1 3 

Ihours, the lithia precipitates in the form of a white 
powder. 

44. Caustic lithia appears not to be much more solu- 
ble in hot than cold water. Heat is evolved during- its 
solution in water. 

OF AMMONIA. 

45. Ammonia is the name given to a substance for* 
merly called volatile alkali. 

46. This substance is distinguished from the fixed al- 
kalies by its comparative volatility, which is such that in 
common temperatures it can be retained in its liquid 
state only, by its combination with water. 

Observation. This substance was unknown to the an- 
cients ; that which they called ammonia or volatile alka- 
li, was ammonia combined with muriatic acid. 

47. Ammonia is caustic but does^ not corrode ani- 
mal matter like potash and soda. 

48. Its most simple state is that of ammoniacal gas or 
vapour, which is lighter than atmospheric air, but not so 
light as hydrogen gas, 

Exp. To procure ammoniacal gas, mix one ounce 
of powdered sal ammoniac with two ounces of quick lime, 
put the mixture into a common flask, and apply a light- 
ed lamp or candle to the bottom, ammoniacal gas will 
rise in abundance. 

f Illustration. Sal ammoniac is composed of ammonia 
and muriatic acid, in this experiment a decomposition 
takes place, the muriatic acid quits the ammonia and 
unites with the lime, for which it has a stronger affinity 
than for the ammonia ; and ammoniacal gas is evol- 
ved. 

49. All animal and vegetable substances disengage 
ammonia when in a state of putrefaction- 



120 IISTKODUCTION 

50. It is procured in the large way, by distilling or bur n* 
ing bones, horns, and other animal substances, hence sal 
ammoniac has been called hartshorn. It was thought 
formerly, that this substance existed only in the horns of 
the Deer and Stag. 

51. Ammoniacal gas has so strong a tendency to unite 
with water that it cannot be procured in the usual way, 
over w T ater, in a pneumatic trough, because it would be 
absorbed by the water, but in order to collect it, a mer- 
curial bath is used. 

52. Water impregnated with this gas is called harts- 
horn, commonly, w r hen spirit is used instead of water, 

spirit of hartshorn, it is the ammoniacal gas issuing from 
water or spirit, that causes the pungent smell, for if a 
phial containing it be left uncorked, the water soon be^ 
comes inodorous. 

53. Water diminishes in density by being impregna* 
ted with ammoniacal gas ; and this augmentation of bulk 
increases its capacity for caloric. 

54. By incorporating with water, the ammoniacal gas 
is liquefied and gives out its latent caloric. The conden- 
sation of the gas more than counterbalance* the expan- 
sion of the water. 

55. Ammoniacal gas mixed with ice or snow produces 
cold. 

Illustration. In this case the water or melted ice, is 
rarefied by the impregnation of the gas, heat of course is 
absorbed, and cold is produced. 

66. Ammonia in the state of vapour combines with 
sulphur and hydroguretted sulphuret of ammonia is pro- 
duced. 

Exp. To form this substance, distil a mixture of five 
parts of sal ammoniac, five parts of sulphur, and six of 
'juick lime together. 

57. Ammoniacal gas unites with muriatic acid gas, 



TO CHEMISTRY. 121 

rbrms the substance called muriate of ammonia, or sal 
ammoniac. 

Exp. Into a small retort put a mixture of two parts 
of quicklime, and one of sal ammoniac, both in powder ; 
apply tire heat of a lamp, and having collected the gas 
into a Urge receiver, convey into it some muriatic gas ; 
from these two invisible gases, a solid substance will be 
obtained in small white flakes. 

58. Ammonia is considered as composed of three vol- 
umes of hydrogen and one volume of nitrogen condensed 
into two volumes. 

59. Its specific gravity compared with that of com- 
mon air is 0.590; 100 cubic inches at a mean tempera- 
ture and pressure weigh 18 grains ; and the weight of 
its atom is 21.25; that of oxygen being considered as 10. 

PRACTICAL QUESTIONS. 

What are alkalies, and how are they distinguished ? 
Do the earths possess any of these properties ? 
What is the cause of alkalies being caustic ? 
How is caustic potash rendered useful for washing ? 
What is the effect of the union of acids and alkalies ? 
How are the alkalies divided ? 
What are they ? 
Why was potash so named ? 
Where is it found ? 
How is potash prepared ? 

What effect does the air have on caustic potash ? 
What quantity of water will dissolve it ? 
Why is heat evolved in dissolving it? 
What is its specific gravity ? 

What are the properties of a pure solution of caustic 
potash ? 

Under what name do surgeons use it ? 
II 



12& INTRODUCTION 

What appearance does it assume in an intense heat? 
Can it be crystallized ? 
What is pearl ash? 
Illustrate it. 

Is potash ever employed in freezing-mixtures ? 
Illustrate this by an example. 

What effect does potash have on all animal matter ? 
What forms glass ? 
Does potash unite with sulphur ? 
Is potash found any where but in vegetables ? 
What effect has potash on blue vegetable colours ? 
Illustrate it by experiment 
With what does potash combine ? 
What may potash be considered to be ? 
What is soda ? 
Where is it found ? 
How may soda be obtained ? 
What are the properties of soda? 
What effect has heat on this substance ? 
Has it any affinity for water ? 
How do you prepare pure soda ? 
What will be the properties of soda thus prepared ;? 
What is Lithia? 

In what was it first discovered ? 
"ilow is it obtained ? 

How does lithia differ from potash and soda ? 
What is the base of lithia called ? 
Does lithia unite with sulphur ? 

What effect has phosphorus on water when united with 
caustic lithia? 

Does lithia dissolve in alcohol ? 
Is lithia more soluble in hot than cold water ? 
Is heat evolved during the solution? 
What is Ammonia ? 



ro CHEMISTBrY, 125 

How is it distinguished from the fixed alkalies ? 

Does ammonia corrode animal substances ? 

In what form is its most simple state ? 

How do you procure ammonical gas ? 

Explain this process. 

When do animal substances disengage ammonia ? 

How is ammonia manufactured ? 

Why cannot ammoniacal gas be produced in the usual 
way ? 

What are water and spirit impregnated with this gas 
called ? 

What eiTect does it have on water ? 

What is the theory of its producing heat in combining 
with w r ater ? 

W T hat does it produce when mixed with ice and snow ? 

Why? 

Does ammonia combine with sulphur ? 

How r is sal ammoniac formed ? 

Illustrate this by an experiment ? 

Of what is ammonia composed ? 

What is its specific gravity ? 



CHAP. XIII. 

Of the decomposition of the Alkalies and Earths, 
1. When Sir H. Davy first turned his attention to the 
agency of the voltaic battery, he tried its power on a 
variety of compound bodies, and gradually brought to 
light a number of new and interesting facts, which led 
the way to more important discoveries. The facility with 
which compound bodies yielded to voltaic electricity in- 



124 INTRODUCTION 

duced him to make trial of its effects on substances hith- 
erto considered as simple, but which he suspected of be- 
ing compound, and his researches were soon crowned 
with the most complete success. 

2. The body which he first submitted to the voltaic 
battery, and which had nerer yet been decomposed, was 
potash. This substance gave out an elastic fluid at the 
positive wire of the galvanic apparatus, and at the nega- 
tive wire small globules of a very bright metallic lustre, 
resembling in appearance mercury. Thus proving that 
potash which had hitherto been considered as a simple 
incombustible body, was in fact a metallic oxide, and 
that its incombustibility proceeds from its being combin- 
ed with oxygen. 

Observation. The wires used in the experiment must 
be platina, for if iron were used, the oxygen would have 
combined with the wires instead of appearing in the form 
of gas. 

S. The base of potash is called po ta $ m m^ and in order 
te preserve it, it must be immersed in naptha. 

4. The properties of potassium are. It is brittle 
and crystallized in its section. It is lighter than water. 
Specifie gravity between 8 and 9 ; water being 10. It 
is very soft and easily moulded between the fingers. At 
the temperature of 150° it is perfectly fluid, very much 
resembling quicksilver. It is volatatiiized in a heat a 
little below that of redness. It is perfectly opaque ; ex- 
posed to the air, it rapid fy attracts oxygen, and becomes 
tarnished. It attracts oxygen much more rapidly from 
water than from air. When thrown upon water, it acts 
with great violence, the water is found to be alka- 
line, and to contain potash; 

Exp. Throw a piece of potassium about the size of 
a pin's head, on the surface of water, it swims and burns 



plate, iv: 




TO CHEMISTRY. 125 

with a- beautiful light, mixed with red and violet. 

5. It burns spontaneously in chlorine with great bril- 
liancy and red light, and forms chloride of potassium. 

Exp. Drop a very small piece into a jar containing 
chlorine, it will immediately inflame. 

6. It inflames spontaneously in the vapour of iodine, 
and consumes with a violet coloured flame ; during the 
inflammation, it absorbs oxygen and sends off hydro- 
gen. 

7. It is soluble in hydrogen gas, forming hydroguret 
of potassium, which becomes inflammable in atmospher- 
ic air. 

8. When potassium is heated in nitrous oxide, it 
burns vividly and potash is formed. 

9. It inflames spontaneously in nitric oxide and upon 
the surface of nitric acid, the products being nitric oxide 
and potash, the potash immediately combines with the 
undecompounded acid to form a nitrate. 

10. Potassium and sulphur combine with great ener- 
gy when heated together, producing much heat and light 
and forming a sulphuret of -potassium. 

11. Sulphuret of potassium is of a grey colour, and 
appears to consist of 30 parts of sulphur and 70 of po* 
tassium. 

12. Potassium combines readily with sodium in vari- 
ous proportions. A small quantity renders sodium very soft 
and brittle, at a common temperature potassium is ren- 
dered fluid and its specifiic gravity is considerably dimin- 
ished. 

13. Potassium may be obtained by chemical means, 
without electricity. 

Exp. If turnings of iron be heated to whiteness in'a 
curved gun barrel, plate 4, fig. 1 and 2, and if melted 
potash be made slowly to come in contact with the turn* - 
*11 



126 INTRODUCTION 

ings, air being- excluded, potassium will be formed and 
will collect in the cool part of the tube : it may likewise 
be produced, by igniting* potash with charcoal. 

The above method of decomposition was invented by 
M. M. Gay Lussac and Thenard. Fig. 1, is a gun barrel 
bent somewhat in the form of the letter S. Before the 
curvatures are given to it, the internal surface must be 
cleaned by stopping one end, introducing into the other, 
diluted sulphuric or muriatic acid, and shaking the bar- 
rel, so that every part may be exposed to the action. — 
After the liquid is poured out, the barrel is to be well 
washed with water, dried by linen or bibulous paper, 
and stepped at both ends. 

The part which is to be exposed to heat from a. to b. 
is to be covered with a lute, which should be formed of 
fine clay and sifted sand, in the proportion of 1 to 5, 
thoroughly incorporated, and rendered so little plastic 
by the quantity of sand as to be applied with some diffi- 
culty. The lute should contain as little water as possi- 
ble. The thickness of the lute over the iron should be 
about T 6 ^ of an inch. It should, after the application, 
be allowed to dry for a few days in the shade, and then 
m the rays of the sun or a gentle heat ; after which, the 
rents, if there be any, should be filled with fresh lute.— 
The space from C; to a. should be filled with clean iron 
turnings, and the barrel is to be laid across a reverbera- 
te ry furnace, fig. 2, having its internal diameter equal to 
ah out 11 1-2 inches; the barrel at a. supporting itself on 
the furnace, and at 6. being supported on a piece of 
brick. The two openings through which the barrel 
passes, aie to be carefully closed with lute ; which, on 
the inside, should consist of that which is the most infusi- 
ble. The cork is then to be drawn from e. and 3 1-2 to 
4 1-2 ounces effused potash in fragments are to be intre- 



TO CHEMISTRY. 127 

duced into the barrel and pushed down to c. fig. 1. Thus 
(he space from f. to c. will be filled with potash, while 
that from f. to e. will be empty. As there is a large 
quantity of gas extricated in this operation, and the other 
end of the tube is liable to be obstructed, a passage is 
given to the gas by fitting a curved glass tube into c. and 
causing its mouth to open into a vessel g. nearly filled 
with mercury, and supported on a stand. Fire is then to 
be lighted in the furnace, and when the fiame appears at 
the dome, pieces of linen, moistened with water, are to 
be applied to the part containing the potash, to prevent it 
from melting ; a recipient is to be adopted to the gun 
barrel at h. fig. 1. 

This consists of two pieces or tubes i. k. of copper, 
the mouth of the barrel bjging inserted into i. and the 
other extremity of i. embracing k. from which passes a 
curved tube that may be made to open under the surface 
of mercury, as seen in fig. 2. The joinings of the tubes 
are to be luted. Then, by means of a double bellows, 
the heat in the furnace is to be raised as high as possi- 
ble ; when this is effected, a semi-cylindrical pan is to be 
suspended below the barrel, reaching from e. to a. The 
portion of the barrel from a. to e. fig. 1, is to be heated 
by live coals ; the potash contained in it will be melted 
and flow into that part which is intensely heated. A 
great quantity of hydrogen gas will be disengaged, and 
a portion of potassium will be formed and condensed at 
the extremity h. and in the recipient i. k. When the 
gas nearly ceases, another portion of the potash higher 
up in the barrei is to be heated ; the gas will again 
come over, and these processes are to be repeated until 
the gas has been extricated from the whole. 

Care must be taken that too much potash should not 
be melted at one time, otherwise the temperature in the 



120 



INTRODUCTION 



first part of the barrel would be reduced too low to effect 
the decomposition of the polish ; hence the reason why 
the alkali is used in fragments and not in a single piece. 
The best sign that the experiment goes on well, is the 
rapid production of gas without the disengagement of 
very thick vapours at the extremity of the glass tube. — 
The duration of the experiment, from the time of the- 
melting of the first portion of potash, should be more than 
an hour. 

When it is finished, the tube at e. should be withdrawn 
from- the mouth of the barrel, and that of the tube at /. 
be closed with lute. The barrel is withdrawn from 
the furnace and cooled by the affusion of cokl water, 
which detaches the lute. 

In order to obtain the potassium which is condensed 
at h. and flows for the most part into the recipient i. k. 
the lute is removed at h. the mouth is closely stopped ; 
a little oil of naptha is poured into the recipient, the 
two pieces are separated and the metal contained in 
them is made to fall into another portion of naptha. The 
potassium thus obtained, is commonly pure, and may be 
best preserved by giving it a spherical form and keeping 
it in naptha. By cutting off the barrel at 6. and plunging 
the end in naptha, the potasssium in it may be obtained by 
introducing into it a cylindar of iron, nearly of the same 
diameter, and detaching it from the surface. 

It happens that, generally, only about half of the pot- 
ash is consumed in the experiment. 

The nature of the lute, and its application and drying, 
are circumstances which have an important influence 
upon the success of the experiment. If it do not con- 
tain sufficient sand, or if it be badly applied or dried, it 
either vitrifies and runs, or it falls oif and exposes the 
iron to oxidizement and fusion. 

Several attempts have been made to simplify the above 



TO CHEMISTRY. 129 

process, and to substitute a more economical one. Pro- 
fessor Gorham succeeded in procuring very good potas- 
sium in the following manner. 

The lower part of a gun barrel properly closed, and 
about 16 inches in length, was luted ; a mixture of dry 
potash and clean iron filings was introduced into it ; a 
tube of copper was then placed in it, but out of reach of 
the strongest heat, and a glass tube was connected with 
the mouth and opened under oil of turpentine. Heat was 
applied until the lute and part of the barrel began to 
melt. On cooling it, 30 or 40 grains of good potassium 
were found condensed in the tube, and as much of an al- 
loy of iron and potassium in the barrel itself. He re- 
peated this experiment five times, in two of which, he 
was successful, and in three, unsuccessful.* 

14. Sodium, the base of soda, is obtained in the same 
way as potassium, only a rather higher degree of heat is 
required. In appearance, it resembles silver ; it is of 
great lustre, and is a conductor of electricity. 

15. It is fusible at 200° F. 

16. It is not volatilized at a heat that melts flint 
glass. 

17. Its specific gravity is 0.97223, water being 1. 

18. It absorbs oxygen from the atmosphere, and burns 
at an high temperature with bright sparks, 

19. Sodium decomposes water w T ith effervescence, 
and is inflamed in contact with nitric acid. 

20. Sodium readily unites with phosphorus and sul- 
phur, and forms compounds, less inflammable than those 
with potassium. 

21. When heated with oxygen or chlorine, it burns 
with great bhlliancy. 

^Gorham 1 3 elements of ehernical science, vol, IL p. 518 



130 INTRODUCTION 

22. Sodium combines with two proportions of oxygea 
The one is that which constitutes soda. The other is 
of a deep orange colour, it is formed by burning sodium 
in oxygen gas, an excess cf the gas being present. 

23. The peroxide of sodium fuses at a much less heat 
than soda ; if thrown into water, one proportion of oxy- 
gen escapes in the form of gas, leaving soda, which dis- 
solves in the water. 

24. Sodium combines with many of the metals form- 
ing peculiar alloys. 

25. When sodium is united with potassium in a small 
proportion, it forms an alloy which is more fusible than 
either of the metals. The compound is of less specific 
gravity, which is not common with other metallic al- 
loys ; and serves to prove that there is not a great affini- 
ty between the metals. 

26. One part of sodium renders 40 of mercury solid 
at the common temperature of the atmosphere ; when 
these combine, heat is disengaged. 

27. Alloys of the metals and sodium when exposed to 
the air, separate the sodium in consequence of its combi- 
nation with oxygen. 

28. When potassium or sodium. is heated in ammonia- 
cal gas, the metal becomes changed to an olive green 
colour, and loses its metallic lustre ; at the same time a 
portion of the gas is absorbed, and a quantity of hydro- 
gen is emitted exactly equal to the quantity that would 
be evolved, if the potassium or sodium were put into 
water, 

29. If the olive green matter be heated, it gives out 
three-fifths of the ammonia absorbed, two-fifths in the 
state of ammoniacal gas, and one-fifth in the state of hy. 
drogen gas and azote. 



TO CHEillSTRV. 131 

30. If the olive coloured matter be placed in contact 
with a very little water, it is converted into potash or 
soda and ammoniacal gas, and the gas is just equal to 
what the metal had absorbed. 

31. If it be placed in contact with a metal and heal- 
ed, an alloy of the metal with potassium or sodium is ob- 
tained. 

Observation. Dr. Thomson is of opinion, that these 
curious facts shew that potassium and sodium have the 
property of decomposing ammonia and combining with 
its azote, and the azotureU or compound of sodium or po 
tassium, formed, combines with a portion of the unde- 
composed ammonia. 

The facts, however, best accord with the opinion that 
an unknown compound of azote and hydrogen unite with 
the alkaline metal, while the compound thus formed, 
combines with a portion of undecomposed ammonia. 

32. From analogy, it has been inferred by some 
chemists, that ammonia contains a metallic base combin- 
ed with oxygen, and many interesting experiments have 
been instituted to ascertain the fact ; further discoveries 
are necessary in proof of the hypothesis. 

33. Some of the earths in like manner have been de- 
composed and found to be oxides of metals. With these, 
metallic alloys have been formed with other metals, 

PRACTICAL QUESTIONS. 
How were the alkalies decomposed ? 
What was the first alkali tried, and what was the pro- 
cess ? 

Why could not iron wire be used in this experiment t 
What is the base of potash called ? 
What are the properties of potassium ? 
Mow can you form chloride of potassium % 



1 32 INTRODUCTION 

What effect has the vapour of iodine upon it ? 

What effect has hydrogen gas in contact with it ? 

What is it in nitrous oxide ? 

What in nitric oxide ? 

What phenomena do potassium and sulphur exhibit, 
when heated together? 

What are the constituents of sulphuret of potassium ? 

What are the combinations of potassium with sodium ? 

How can potassium be obtained without electricity ? 

Describe Gay Lussac's and Thenard's apparatus ? 

Will any hydrogen gas be disengaged ? 

How do you give a passage to the gas ? 

Is it essential to attend to the quantity of potash ? 

Why? 

How do you know that the process goes on well ? 

How do you obtain the potassium, after the experi- 
ment ? 

How can it be preserved ? 

How much of the potash is consumed in this experi- 
ment ? 

Is there any alloy formed ? 

What should be the nature of the lute ? 

Has this process been simplified ? 

Describe Professor Gorham's process ? 

How much good potassium did he obtain ? 

Was there any alloy ? 

How is sodium obtained ? 

At what temperature is it fusible ? 

When is it volatilized ? 

What is its specific gravity ? 

Does it absorb oxygen from the atmosphere ? 

Does sodium unite with phosphorus and sulphur ? 

What is the effect, when heated with oxygen or chlb- 
rine? 



TO CHEMISTRY, 133 

With how many proportions of oxygen does sodium 
combine, and what are their properties ? 

What are the phenomena attending the peroxide of 
chlorine ? 

Does sodium combine with any of the metals ? 

What is the compound of sodium with potassium ? 

What effect has sodium on mercury ? 

What effect does the air have on alloys of metal, with 
sodium ? 

What effect has ammoniacal gas on sodium and potas- 
sium ? 

When the olive green matter is heated, what does it 
exhibit ? 

What, when placed in contact with water ? 

When placed in contact with a metal and heated, what 
does it exhibit ? 

What is the opinion of Dr. Thomson, on this subject ? 

How do chemists infer that ammonia has a metallic 
base ? 

Have the earths been decomposed ? 



CHAP. XIV. 

On the Earths. 

1. The term earth in chemistry is applied to those 
bodies, which, until the 19th century, were all regarded 
as simple substances, and from the different combination 
of which, all those substances are formed, which are 
usually classed as earths and stones. 

2. The number of substances classed under the name 

uf earths, hitherto discovered, are ten, viz. 
12 



134 INTRODUCTION 

1. Barytes, 4. Magnesia, 7. Glucina. 

2. Strontian, 5. Alumina, 8. Zirconia, 

3. Lime, 6. Yttria, or Ittria, 9. Silica, 

10. Thorina. 

3. From recent discoveries, some have been led to 
conclude, that all earths are metallic oxides ; but this 
has not been ascertained. 

4. Their properties are ; they do not combine with 
metals, but have an affinity for some of the metallic ox- 
ides. 

5. They are divided by some chemists into two classes, 
viz. those which possess merely the characteristics of 
earths, which are insoluble in water or alcohol, or nearly 
so. When perfectly pure, they are in the form of white 
powder, destitute of smell or taste, infusible, and unal- 
terable in the air. 

6. The second class are those, which not only possess 
the above properties, but likewise those of an alkaPne 
nature, having a strong taste, soluble, in some measure, 
in water and alcohol, and changing vegetable blues to 
green. 

7. According to Sir H. Davy, the earths found in 
plants, are four, viz. silica, or the earth of flints ; alumi- 
na, or pure clay ; lime and magnesia. The lime is usu- 
ally combined with carbonic acid. 

8. Lime and silica are much more common in the 
vegetable kingdom than magnesia ; and magnesia more 
than alumina. 

9. The earths form a principal part of the matter of 
the ashes of plants, insoluble in water. The silica is 
distinguished by its insolubility in acids. The calcareous 
earth, unless the vegetable substance be very strongly 
ignited, dissolves with effervescence in muriatic acid. — 
Alumina is distinguished from the other earths, by being 



TO CHEMISTRY, 135 

dieted upon very slowly by acids, and by forming salts 
very soluble in water, and difficult of crystallization. 

10. It is on the principle of the incombustibility of 
earth, that its power of producing such an intense heat 
when mixed with other substances, arises, as in turf or 
peat) &c. 

11. Turf is composed of roots, grass, the remnants of 
animal and vegetable substances, together with alumina, 
lime, silex, and sometimes magnesia. 

12. In combustion, it is not the earths that burns, but 
the vegetable and animal substances; The caloric which 
is produced by this combustion, causes the earth to be- 
come red ho^ and this being a bad conductor of heat, re- 
tains its caloric a long time ; but the earth does not ab- 
sorb oxygen or undergo any alteration in the fire. It is, 
however, an excellent radiator of heat, and owes its 
utility, when mixed with fuel, solely to that property. 

Illustration. On this principle, Count Rumford recon> 
mended balls of incombustible substances to be arranged 
in fire places, and mixed with the coals, by which means 
the caloric disengaged by combustion of the latter, is 
more perfectly radiated, and an expense of fuel is saved. 

13. Precious stones are composed of a number of 
earths, sometimes salts, and even metals. 

14. The earths are often found crystallized in pre- 
cious stones, which must have been a slow and regular 
work of ages. 

Illustration. To account for the slow and gradual 
crystallization of earths in precious stones, seeing they 
are almost insoluble in water, we may imagine, that 
when water holding in solution some particles of earth, 
filters through the crevices of hills and mountains, and 
at length, drops into some cavern, each successive drop 
may be slowly evaporated, leaving behind it the particle 



136 INTRODUCTION 

of earth which it held in solution. Crystallization is 
more regular and perfect in proportion to the evapora- 
tion of the solvent ; in this case, nature has an advantage 
over the artist \ she carries on her operations unlimited 
by time, nor retarded in her gradual progress. 

15. In examining the earths, we must take them as 
they are usually found in nature, and not when wrought 
or modified by art. 

OF BARYTES. 

16. Barytes has Jts name from its weight; it is the 
heaviest of the earths. It is usually found in the state 
of a sulphate. 

17. The characteristics of pure barytes are, great 
weight, strong alkaline properties, such as turning some 
blue vegetable colours to green, destroying animal sub- 
stances, and shewing a powerful attraction for acids. 

18. Its affinity for the sulphuric acid is so great, that 
it will always detect its presence in any substance or 
combination whatever, by immediately uniting with it 
and forming a sulphate. 

Exp. 1. Dissolve in a glass of water one grain of 
sulphate of soda, and add to it a few drops of nitrate of 
barytes in solution, w r hite clouds will be immediately 
formed. 

I llv strati 'on. Barytes has a stronger affinity for sulphu- 
ric acid than any other bouy, forming with it, in this in- 
stance, a sulphate of barytes, which is one of the most 
insoluble substances, and the soda unites with the water. 
This property of barytes renders it an excellent test for 
detecting the presence of any quantity, however small, 
of sulphuric acid. 

Exp. 2. To shew its alkaline properties on vegetable 
colours, tinge water with Brazil wood, by an addition of 



TO CHEMISTRY. 137 

a small quantity of a solution of barytes, the red will be 
changed to violet. 

Exp. 3. In a glass of distilled water, rendered slight- 
ly blue by the tincture of red cabbage, drop a few grains 
of the solution of barytes, the blue will be changed to 
green. 

19. Barytes combines with sulphur, when they are 
mixed together and heated in a crucible. 

20. Sulphuret of barytes is cf a reddish yellow col- 
our, ^ind when dry, without smell. When thrown into 
hot water, a powerful action takes place. The water is 
decomposed, and two new products are formed, viz. hy~ 
dro-sulphuret, and hydro guretted sulphuret of barytes. The 
first, crystallizes as the liquor cools ; the second, remains 
in solution. 

21. The hydro-sulphuret of barytes contains 9.7 of 
barytes, and 2.125 sulphuretted- hydrogen. 

22. The crystals are white scales, have a silky lus- 
tre, are soluble in water, and yield a solution having a 
greenish tinge. Taste acrid, sulphurous, and when mix- 
ed with the hydroguretted sulphuret, is corrosive. It 
rapidly attracts oxygen from the atmosphere, and is con- 
verted into sulphate of barytes. 

23.» The hydroguretted sulphuret is a compound of 
9.70 barytes and 4.125 bisulphureited hydrogen, or hydro- 
gen with two proportions of sulphur ; it is contaminated 
with sulphite and hyposulphite in unknown proportions. 

24. Barytes combines with phosphorus. It may be 
easily formed by exposing the constituents together, to 
heat in a glass tube. Their reciprocal action is so in- 
tense as to cause ignition. 

25. Like phosphuret of lime, it decomposes water, 
and causes the disengagement of phosphuretted hydrogei* 

12* 



138 INTRODUCTION 

gas, which spontaneously inflames in contact with the 
air. 

26. Barytes has been decomposed and found to con- 
tain a metallic base, called barium. It is of a dark grey 
colour, with a lustre inferior to that of cast iron. It is 
fusible at a red heat; its density is superior to that of 
sulphuric acid. When exposed to air, it instantly becomes 
covered with a crust of barytes, and when gently heated, 
burns with a deep red light. It effervesces violently in 
water, converting this liquid into a solution of barytes. 

27. Barium combines with oxygen in two proportions, 
forming, 1st. barytes, and 2d. deutoxide of barium. 

28. The salts of barytes are white, and more or less 
transparent. They are all poisonous except the sul- 
phate ; hence the counterpoison is the sulphuric acid 
diluted for the carbonate, and sulphate of soda, for the 
soluble salts of barytes. 

OF STRONTIAN. 

29. Strontia or strontian is so named from a place in 
Scotland, where it was first discovered. 

30. Pure strontian is of a greyish white colour, and a 
pungent acrid taste. Its specific gravity is nearly that of 
barytes, being about 1.6. It is soluble in 200 times its 
weight of water at 50°, but little more than six times its 
weight at 212°. On cooling, it deposits flat rhomboidal 
crystals. It is likewise soluble in small proportions in 
alcohol. Exposed to heat, these crystals undergo aque- 
ous fusion, and become dry ; in this dry state, it requires 
the heat of the oxyhydrogen blow pipe to fuse it* 

31. Strontian differs from barytes in being infusible, 
but at a very intense temperature, much less soluble, of 
a different form, weaker in its affinities, and not poison- 
ous. Its saline compounds afford differences much mere 
distinguishable. 



TO CHEMISTRY. 139 

32. The basis of strontian is strontium, It is fixed, 
difficulty fusible, and not volatile. It is converted into 
strontian on exposure to the air, and when thrown into 
water, decomposes it with great violence, producing- hy 
drogen gas and a solution of strontian. Strontian is con- 
sidered as composed of about 86 strontian + 14 oxygen 
in 100 parts. 

33. Strontian when mixed with inflammable substan- 
ces, causes a flame of a beautiful red colour. 

Exp. 1. Take 40 parts dry nitrate of strontian, 13 
parts of finely powdered sulphur, 5 parts oxymuriate of 
potash, (chlorate) and 4 of sulphuret of antimony. PuU 
verize the oxymuriate of potash, and sulphuret of anti- 
mony separately in a mortar, and then mix them togeth- 
er on paper ; after which, add them to the other ingre- 
dients, previously powdered and mixed. Rub them to- 
gether on paper, and a beautiful red flame of great bril- 
liancy will be produced. 

Exp. 2. Add a little of the solution of muriate of 
strontian to alcohol, kindle it, and red flames will be 
produced. 

Exp. 3. Sprinkle a little of powdered muriate of 
strontian on the flame of a candle, and the flame will as- 
sume a carmine colour* 

34. Strontian is slightly caustic, acting feebly on ani- 
mal matter. It diners from barytes, in being infusible, 
much less soluble, of a different form, weaker in its affin- 
ities, and not poisonous. 

OF LIME. 

35. Lime is the oxide of calcium, a name given to 
the base of lime. It is generally combined with carbonic 
acid in lime stone, marble and chalk, and is essential to 
the constitution of marles. 



140 INTRODUCTION 

36. When deprived of carbonic acid, it possesses a- 
caustic and corrosive quality r and is called quick lime. 

Exp. Expose carbonate of lime to a strong heat in a 
crucible, carbonic acid and water is disengaged, and the 
result is-quick lime. 

37. Carbonate of lime loses by calcination 40 per 
cent of its weight. 

38. Pure lime has such an affinity for carbonic acid 
and water, that it cannot be preserved for any length of 
time but in glass vessels, closely stopped. 

39. When water is added in small quantities to quick 
lime, the water is solidified, and heat is evolved. 

Exp. Pour a little water on a lump of quick lime, 
the water immediately disappears, and heat is produced. 

Illustration. The heat proceeds not from the lime, 
but from the water, and is the latent which causes the 
liquidity of the water. 

40. Lime requires nearly 700 times its weight of wa- 
ter for its solution ; in this state, it is called lime water. — 
When first made, it is perfectly clear, and colourless ; 
but it soon attracts carbonic acid from the atmosphere, 
and a pellicle is formed on the surface. 

Exp. 1. Expose lime water in a glass, for a few min- 
utes, to the air, the lime separates from the water, and 
appears on the surface in the form of a white film, 
which is carbonate of lime or chalk. 

Exp. 2. Breathe into a glass of lime water, the car- 
bonic acid which , is mixed with the air expired, will 
separate the lime as in the last experiment. 

41. Carbonate of lime is soluble in carbonic acid, but 
not soluble in water. 

42. Lime water possesses alkaline properties, for 
when poured into blue vegetable infusions, they turn 
green. 



TO CHEMISTRY. 141 

43. Lime water, mixed with mild alkali in solution, 
disengages the carbonic acid, and precipitates the lime in 
a white powdery form, and the alkali is left pure. 

44. The specific gravity of lime is 2.3. 

45. It requires an intense degree of heat for its fu- 
sion, and has not been volatilized. Its taste is caustic, 
astringent and alkaline. 

46. Slacked lime is called hydrate of lime, in conse 
quence of its combination with water. Its solubility is 
not increased by heat. 

47. Slacked lime is a compound of 3.56 parts lime,and 
1.125 water. 

48. Lime combines with phosphorus, and forms a 
compound of a dark brown colour, called phosphuret of 
lime ; which, when thrown into water, disengages phos- 
phuretted hydrogen gas in small bubbles, that explode in 
succession, at the surface of the water. 

Exp. Provide a glass tube sealed at one end, into the 
sealed end put a small bit of phosphorus ; the middle 
part must be filled with pieces of lime, about the size of 
peas. After heating the latter with a lamp, apply anoth- 
er lamp to the end containing the phosphorus, and cause 
the vapour to pass through the lime, the combination 
will be completed. 

49. Sulphur combines with lime, by fusing the con- 
stituents together in a covered crucible. It is called sul- 
phuret of lime. 

50. It possesses the following properties. It is of a 
reddish colour, and very acrid. It deliquesces on expo- 
sure to the air, and becomes of a greenish yellow hue.—** 
When it is put into water, hydroguretted sulphuret of 
lime is immediately formed. It acts corrosively on ani- 
mal bodies, and is a powerful reagent in precipitating 
metals from their solutions, 



142 INTRODUCTION 

51. Lime combines with chlorine and forms a sub- 
stance called chloride of lime or calcium. When lime 
is heated in contact with chlorine, oxygen is expelled, 
and chlorine is absorbed. 

52. It is a semi-transparent crystalline substance, fu- 
sible at a strong red heat; a non-conductor of electricity ; 
has very little taste ; rapidly absorbs w r ater from the at- 
mosphere, and is very soluble in water. 

53. Lime has a metallic base, called" calcium; it is of 
a bright silvery appearance, and combines with oxygen 
only in one proportion, which is lime. It burns when* 
gently heated, producing dry lime. 

54. The most important applications of lime are in 
agriculture and building. 

55. Quicklime is found to be injurious to plants, but 
in its combination with carbonic acid, it is an important 
ingredient. 

56. Lime acts as a cement in two ways ; in its combi- 
nation with water, and in that of carbonic acid. 

57. When quicklime is rapidly made into a paste with 
water, it soon loses its softness ; the water and the lime 
form together a solid coherent mass, which consists of 1 
part of water to 3 parts of lime. When hydrate of lime, 
whilst it is consolidating, is mixed with red oxide of iron, 
alumina, or silica, the mixture becomes harder and more 
coherent, than when lime alone is used. 

Illustration. This is owing to a certain degTee of 
chemical attraction between hydrate of lime and these 
bodies, and they render it less liable to decompose by 
the carbonic acid in the air, and less soluble in water. 

58. The basis of all cements that are used for works 
which are to be covered with water, must be formed- 
from lime^ 



to CHiaitegur, 143 

59. Puzzolano is composed principally of silica, alu- 
mina and oxide of iron ; and it is used, mixed with iron, 
to form cements intended to be employed under water. 

60. Tarras, is basaltes decomposed, two parts of slack- 
ed lime, and one of tarras, form the cement used in con- 
structing the great dykes in Holland. 

PRACTICAL QUESTIONS. 

To what is the term earth applied ? 

What are the names and number of the earths ? 

What are the earths considered to be ? 

How are they divided by some chemists ? 

What do these classes include ? 

What are the earths found in plants ? 

Which are the most common in vegetables ? 

What part of the ashes of plants do they form ? 

From what does the power of producing intense heat 
in turf and peat, arise ? 

Of what is turf or peat composed ? 

What use are earths in combustion ? 

What was Count Rumford's recommendation ? 

Of what are precious stones composed ? 

In what state are the earths found in precious stone9 ? 

How do you account for this ? 

How must you proceed in examining the earths ? 

What is barytes ? 

What are its properties ? 

How is its affinity for sulphuric acid ? 

What experiment can you adduce to prove this ? 

Illustrate the principle. 

How do you shew its alkaline properties on vegetaj 
bles? 

Will barytes combine with sulphur ? 

What are the properties of sulphuret of barytes ? 



144 INTRODUCTION 

What are the constituents of hydrosulphuret of barytes? 

What are the properties of the crystals of the hydro- 
sulphuret ? 

What is the hydroguretted sulphuret ? 

How may phosphuret of barytes be formed "? 

What are its properties ? 

W^hat are the characteristics of barium ? 

In how many proportions does it combine with oxy- 
gen ? 

What property do the salts of barytes possess ? 

What is strontian ? 

What are the characteristics of strontian ? 

How does it differ from barytes ? 

What is the basis of strontian, and its properties ? 

What effect has strontian on inflammable substances ? 

How would you illustrate this by experiment ? 

is strontian caustic ? 

What is lime ? 

What does it possess, when deprived of carbonic acid ? 

How much does carbonate of lime lose by calcination ? 

How can you preserve pure lime ? 

What is the effect, when small quantities of water are 
added to quicklime ? 

Illustrate this. 

How much water does lime require for its solution I 

How will you prove that water attracts carbonic acid 
from the atmosphere ? 

In what is carbonate of lime soluble ? 

How do you prove that lime water possesses alkaline 
properties ? 

What effect has mild alkali on water ? 

What is the specific gravity of lime ? 

Can lime be fused and volat ilized 

What is slacked lime called ? 



TO CHEMISTRY. 145 

Of what is it compounded ? 

What is the combination of lime with phosphorus ? 

How would you prepare phosphuret of lime ? 

How is sulphur combined with lime ? 

What properties does it possess ? 

What is chloride of-lime ? 

What are its properties ? 

What is the base of lime ? 

What are the most important applications of lime ? - 

What effect has it on vegetation ? 

How does lime act as a cement 

What is the effect of quicklime, when rapidly made 
into a paste with water ? 

Is there any way to render mortar harder and more 
coherent, than when lime alone is used ? 

To what is this owing ? 

Of what must be the basis of all cements that are cov- 
■ered with water? 

What is Puzzolana ? 

What is Tarras '? 



CHAP. XV. 

Of Magnesia — Alumina^Yttria—Glucin&~Zirconia~~ 
Silica, and Thorina. 
1. Magnesia is never found pure in nature, but is 
Usually procured from the sulphate of magnesia, Epsom 
Salt, which exists in sea water, and in mineral springs. 

Exp. Dissolve the sulphate of magnesia in watery 
and add to it half as much in weight of pure jotash; & 
13 



146 INTRODUCTION 

decomposition takes place, the sulphuric acid of the sul- 
phate unites with the potash in consequence of superior 
affinity, and the magnesia is precipitated. Wash the 
precipitate several times with pure water, and the mag- 
nesia in a state of an hydro-carbonate will be obtained. 
To procure it pure, calcine it in a crucible, until it will 
do longer effervesce with distilled vinegar. 

2. Magnesia, when pure, is destitute of smell, and has 
a slight alkaline taste. It inverts vegetable blues to 
green, gives out heat like lime, on the affusion of water. 
It is very sparingly soluble in water, requiring for its so- 
lution 2000 times its w r eight. It forms with acids ex- 
tremely soluble salts. 

3. The specific gravity of magnesia is 2.3. 

4. It is infusible, except by the oxyhydrogen blow 
pipe. It has scarcely any taste or smell. 

5. When precipitated from the sulphate, it is combin- 
ed with w r ater, constituting an hydrate, which separates 
by a red heat. 

6. This hydrate contains about one fourth its weight 
of water. 

7. When magnesia is exposed to the air, it very slow- 
ly attracts carbonic acid. 

8. Magnesia combines with sulphur, forming a sul- 
phuret. 

9. The magnesia of commerce is often found mixed 
with carbonate of lime ; if this be the case, sulphuric 
acid will detect the fraud ; it dissolves the magnesia, 
while the lime falls to the bottom. 

Exp. Take a small quantity of magnesia, and add a 
little sulphuric acid, diluted with five or six times its 
weight of water ; if the solution be transparent, it is 
pure, but if there be a sediment, it may be considered as 
mixed with lime. 






TO CHEMISTRY. 147 

10. The base of magnesia is called magnesium, and 
may be obtained by passing potassium in vapour through 
it, heated to whiteness in a tube of platinum, out of con- 
tact of the air, and then introducing a small quantity ©f 
mercury, and heating it gently in the tube ; an amalgam 
is obtained, which mu?t be distilled, excluded from the 
atmosphere, a dark grey metallic film will be obtained, 
which is infusible at the point at which plate glass soft- 
ens, and which in the process of the distillation with the 
mercury, renders the glass black at its point of contact 
with it. 

11. The film as above obtained, burns with a red 
light when strongly heated, and becomes converted into 
a white powder, which is magnesia. 

12. When exposed to the air, magnesium absorbs oxy- 
gen, and is converted into magnesia. 

13. According to late experiments, magnesia consists 
of 60 parts magnesium, and 40 oxygen. 

14. Magnesia is found to exist in talc, asbestos, amian- 
thus slate, and in a certain limestone, which contains it 
in very great quantities. 

15. Its principal use is in medicine, chiefly to com- 
bine with, and neutralize the acids found in the stomach. 

OF ALUMINA. 

16. Alumina derives its name from the compound 
salt called alum, or more properly sulphate of alumina, 
of which it forms the base. The purest native alumina 
is found in the sapphire and ruby. 

Exp. Dissolve alum, sulphate of alumina, in 20 times 
its weight of water, and add to it a little of the carbonate 
of soda, to throw down any iron that there may chance 
to be combined with it ; then pour the supernatant liquid, 
a little at a time, into the water of ammonia r taking care 



148 INTRODUCTION 

not to add so much as to saturate the ammonia ; the am- 
monia will unite with the sulphuric acid of the alum, and 
the earthy basis of the latter is separated in a white 
spongy precipitate. This must be thrown on a filter, 
washed with pure water, and then dried. 

17. Alumina thus obtained, possesses the following 
properties. It is white, soft to the touch, adheres to the 
tongue, forms a smooth paste without grittiness in the 
mouth, insipid, inodorous, produces no change in vegeta- 
ble colours, insoluble in water, but mixes with it readily 
in every proportion, and retains a small quantity with 
considerable force. It is infusible in the strongest heat of 
a furnace, becoming merely more compact and hard. It 
is fusible in small quantities by the oxyhydrogen blow 
pipe. 

18. In the state of powder, its specific gravity is 
2.000. 

19. From analogy, we are led to conclude, that the 
base of alumina is a metal possessing similar properties 
as other earthy bases ; but this subject has not been ful- 
ly investigated. 

20. Alumina is a constituent of every soil, and almost 
every rock. It is the basis of pottery, bricks and cruci- 
bles. 

21. In the state of clay, it forms large strata of the 
e^rth, gives consistency to the soil of valleys, and of all 
low and damp spots, such as swamps and marshes. 

22. The solid compact soils, such as are fit for corn, 
owe their compactness in a great measure to alumina, 
This earth is therefore used to improve sandy or chalky 
soils, which do not contain a sufficient quantity of water 
for the purpose of vegetation, 

23. Combined with silex and water, which harden it, 
alumina forms bricks and porcelain ; the silex renders it 



TO fcnfeSISTftY. 149 

capable of a degree of vitrification, and makes it per- 
fectly fit for its various purposes. 

24. Bricks consist of baked clay, silex, or common 
sand, and an oxide of iron to which they owe their red 
colour. 

25. The common earthen ware is made of clay and 
sand. 

26. For porcelain, the purest kind of sand is used, 
with the best kind of clay ; it owes its semi-transparency 
to a kind of vitrification of the sand. 

27. Earthen ware and por celain are covered with a 
glazing, to render them more beautiful, and to prevent 
their being corroded by a variety of substances. 

28. The glazing for porcelain consists of enamel, a 
fine white opake glass, formed of metallic oxides, sand, 
salt, and such other materials as are susceptible of vitri- 
fication. 

29. The glazing of common earthen ware is made 
principally of the oxide of lead, or sometimes merely of 
common salt, as for stone ware ; this, at a certain tem- 
perature, will run into an opake glass. 

30. The colours used for painting porcelain are all 
metallic oxides, capable of enduring a great degree of 
heat without injury ; by undergoing different degrees of 
oxidation, the colours are strengthened and developed. 

Illustration. The oxide of gold is employed for pur- 
ple, red is given by the oxide of iron, yellow by the ox- 
ide of silver, green by copper, and blue by cobalt. 

31. Alumina has a strong affinity for vegetable col- 
ouring matter, and is used as a mordant by the dyer and 
calico printer. 

32. Alumina is found combined in different propor- 
tions, in various gems and other minerals. Many of the 

13* 



1 50 INTRODUCTION 

precious stones are almost wholly formed of alumina, 
coloured with some metallic oxide. 

Observation, Such as ruby, oriental, sapphire, ama- 
thysts, &c, 

33. Ful!e?*s earth is a compound of alumina and silex 
It is of great importance in scouring cloth, and in taking 
out spots of grease from the floor and other substances, 
from the affinity which alumina manifests for greasy 
substances, 

34. On the principle, that the bulk of alumina dimin- 
ishes in proportion to the heat to which it is exposed, is 
founded the pyrometer of Mr. Wedgwood, for measuring 
high degrees of temperature. 

35. The salts of alumina possess the following charac- 
ters, 

1. Most of them are very soluble in water, and their 
solutions have a rough sweetish taste. 

2. Ammonia precipitates their earthy base, even 
though they have been previously acidulated with mu- 
riatic acid. 

3. At a strong heat, they give out a portion of their 
acid. 

4. Phosphate of ammonia gives a white precipitate. 

5. Hydriodate of potash produces a flocculent precipi- 
tate of a white colour, passing into a permanent yellow. 

6. These salts are not affected by oxalate of ammonia, 
tartaric acid, ferroprussiate of potash, or tincture of 
galls ; by the first two tests they are distinguished from 
yttria, and by the last two from that earth and glucina. 

7. If bisulphate of potash be added to a solution of an. 
aluminous salt, moderately concentrated, octahedral crys- 
tals of alum will form. 



TO CHEMISTRY, 151 

OF YTTRIA, OR ITTRIA. 

36. Yttria is an earth, discovered in 1794, in a stone 
kom Ytterby in Sweden, by professor Gadolin. 

37. It is perfectly white, when not contaminated with 
oxide of manganese, from which it is not easily freed.-— 
Its specific gravity is 4.842. It has neither taste nor 
smell. It is infusible by itself, but when mixed with 
borax, melts into a transparent glass. It is insoluble in 
water and caustic fixed alkalis, but is soluble in carbo- 
nate of ammonia. It is soluble in most of the acids. 

38. Yttria is considered as having a metallic base 
similar in its properties to the bases of the other earths^ 
and is called Yttrium. 

OF GLUCINA. 

39. Glucina is an earth obtained from the beryl or 
emerald, a transparent stone of a green colour, found 
crystallized in the mountains of Siberia. It was discov- 
ered by Vauquelin. 

40. Glucina derives its name from the Greek word 
signifying sweet, because it imparts a saccharine taste to 
all the acids with which it unites, and forms salts,, 

41. It is a white soft powder, light, insipid and ad- 
hering to the tongue. It does not change vegetable 
blues. It does not harden by heat, and is infusible. It 
is insoluble in water, but forms with it a slight ductile 
paste. It is dissolved by potash, soda and carbonate of 
ammonia, but not by pure ammonia. It unites with sul- 
phuretted hydrogen. Its salts have a, saccharine taste,, 
with somewhat of astringency. 

42. Glucina is considered as a compound of oxygem 
and a certain metallic base called Glucinum. 



1 52 inthoditction 

of zirconia. 

43. Zirconia is a substanc-3 found in the zircon or 
jargon, and the hyacinth. 

44. It possesses neither taste nor smell. It is infusi- 
ble before the blow pipe, but when subjected to a very 
high temperature in a charcoal crucible, it undergoes a 
sort of imperfect fusion, acquires a greyish colour, and a 
porcelaneous appearance. It is insoluble in water, or in 
the alkaline solutions. Its specific gravity is 4.3. 

45. Zirconia has a considerable affinity to water, and 
when precipitated from its acid solutions, it is called an 
hydrate, which has the appearance of rosin or glue. 

46. The hydrate contains more than 20 per cent of 
w r ater, which may be expelled by heat. 

47. Zirconia is considered as a compound of a metal 
and oxygen. Potassium when brought into contact with 
zirconia, ignited to whiteness, is, for the most part, con- 
verted into potash ; and dark particles, which, when ex- 
amined by a magnifying glass, appear metallic in some 
parts, of a chocolate brown in others, are found diffused 
through the potash and the decompounded earth. 

OF SILICA. 

48. Silex or silica abounds in almost all fossils and 
precious stones, particularly those which strike fire with 
steel. It exists nearly pure in transparent quartz or rock 
crystal. 

Exp. To obtain silica, ignite powdered quartz with 
three parts of pure potash in a silver crucible, dissolve 
the fused compound in water, add to the solution a quan- 
tity of acid, sufficient to saturate the alkali, then evapo- 
rate to dryness, a fine gritty powder will be obtained, 



TO CHEMISTRY. 1 §S 

which being well washed with distilled water, and ignit- 
ed, will leave pure silica. 

49. It is a white powder, of a harsh and gritty feel, 
Specific gravity 2.6G. It is fusible only by the oxyhy- 
drogen blow pipe. It is acted upon by no acid, but the 
fluoric, and appears to be insoluble in water, although 
nature by some process dissolves it, and crystallizes it 
in the form of rock crystal 

50. The value of siliceous earth in many arts is very 
extensive. It is used in the manufacture of glass, potte- 
ry, bricks, porcelain, &c. It likewise forms one of the 
ingredients of the most durable mortars and cements* 

51. Silica and potash, or soda fused together, form 
glass. It is of different qualities, according to the ingre- 
dients used. 

Illustration. Flint glass is formed of soda or potash, 
flints, and an oxide of lead. Window glass is composed 
of an alkali and fine sand. Bottle glass of kelp and com- 
mon sand ; its green colour is owing to the presence of 
iron. 

Exp. Take one part of pure white sand, and three 
parts of potash, mix them into a paste, and fuse them in 
a crucible, the result is glass. 

52. Silica is considered as a compound of a peculiar 
combustible principle with oxygen. By passing the va- 
pour of potassium over silica in an ignited tube, Sir H. 
Davy obtained a dark coloured powder, which contained 
silicon, or the basis of silica. 

53. It is capable of sustaining an high temperature, 
without any change ; water of potash seems to form 
with it an olive coloured solution. But as this basis is 
decomposed by water, it is not possible to wash away 
the potash by this liquid. Berzelius and Stromeyer tri- 
ed to fprm a compound of silicon with iron, by exposing 



154 INTRODUCTION 

to the strongest heat of a blast furnace, a mixture of 3 
parts of iron, 1.5 silica, and 0.66 charcoal. It was in the 
state of fused globules. These freed from the charcoal, 
were white and ductile, and their solution in muriatic 
acid evolved more hydrogen, than an equal weight of 
iron. The specific gravity of the alloy was from 6.7 to 
7.3, while that of the iron used was 7.8285. Nothing 
definite, however, can be inferred from these experi- 
ments. 

54. Sir H. Davy found that more than three parts of 
potassium were necessary to decompose one of silica. — 
Hence it maybe inferred, that 100 parts of silica contain 
about 60 of oxygen. 

55. Silicon is insoluble in alcohol, ether, or the oils, 
at any temperature, and is a non-conductor of electricity. 

56. Silica forms with fluorine, a substance which 
though not sour, seems to partake of the properties of 
an acid, and called Jlao-silicic acid^ or silicated Jluoric 
acid. 

OF THORINA. 

57. Thorina is a new earth, discovered in 1816, by 
Berzeiius. He found it in small quantities in the gadoli- 
nite, and two new minerals, which he named the deuto- 
fluate of cerium, and the double fluate of cerium and 
yttria. 

58. It has the appearance of a gelatinous semi-trans- 
parent mass. When washed and dried it becomes white, 
absorbs carbonic acid, and dissolves with effervescence 
in acids. When dissolved in muriatic acid, the solution 
has a yellowish colour, but it becomes colourless when 
mixed with water. 

59. It differs from all other species of earths, except 
zirconia ; in this, that the neutral solutions have a pure- 



TO CHEMISTRY. 155 

Ij astringent taste, which is neither sweet, saline, bitter, 
nor metallic, 

60. When dissolved in sulphuric acid, with a slight 
excess of acid, and subjected to evaporation, it yields 
transparent crystals, which are not altered by exposure 
to the air, and which have a strong styptic taste* 

61. It is soluble in nitric and muriatic acids, and com* 
Lines with avidity with carbonic acid. 

62. Thorina differs from zirconia by the following 
properties. 1. After being heated to redness, it is still 
capable of being dissolved in acids. 2. Sulphate of pot- 
ash does not precipitate it from its solution, while it pre- 
cipitates zirconia containing even a considerable excess 
of acid. 3. It is precipitated with oxalate of ammonia, 
which is not the case with zirconia. 4, Sulphate of 
thorina crystallizes readily, while sulphate of zirconia, 
when free from alkali, forms, when dried, a gelatinous 
transparent mass, without any trace of crystallization. 

63. The supposed metallic base of thorina, is called 
Thorinum. It has not yet been extracted. 

PRACTICAL QUESTIONS. 

How is magnesia procured ? 

Illustrate it by experiment. 

What are the properties of magnesia ? 

What is its specific gravity ? 

Is it fusible ? 

What is the hydrate of magnesia ? 

How much water does it contain ? 

What is the effect on magnesia when exposed to the 
air? 

With what is the magnesia of commerce mixed, and 
how is the fraud detected ? 

How is the base of magnesia obtained ? 



156 Introduction 

How do you prove that this film is magnesia ? 

Of what does magnesia consist ? 

Where is magnesia found to exist ? 

What is the use of magnesia ? 

What is alumina ? 

How do you procure pure alumina? 

What are the properties of alumina thus obtained t 

What is its specific gravity ? 

How do you conclude that the base of alumina is a 
metal ? 

Of what is alumina the constituent ? 

What does it form in the state of clay ? 

What use is this earth in agriculture ? 

Of What use is silex in forming bricks and mortar ? 

Of what do bricks consist ? 

Of what is common earthen ware made ? 

What is used for porcelain ? 

What is the use of glazing earthen ware and porce- 
lain ? 

Of what does the glazing for porcelain consist ? 

Of what is the glazing of common earthen ware and 
stone ware made ? 

What are the colours used for painting porcelain ? 

Why is alumina used as a mordant ? 

Where is alumina found ? 

What is fuller's earth, and why does it remove grease 
spots ? 

On what principle is Wedgwood's pyrometer formed ? 

What are the characteristics of the salts of alumina^ 

What is yttria ? 

What are its characteristics ! 

Has it a metallic base ? 

What is glucina ? 

From what does it derive its name f 



TO CHEMI«TR\. 157 

What are its characteristics ? 

What is glucina considered to be ? 

What is zirconia ? 

What are its properties ? 

Has it any affinity for water ? 

How much water does the hydrate contain ? 

How is it proved that zirconia has a metallic base 

Where is silex or silica found ? 

How do you obtain it pure ? 

What are its properties ? 

Is silica of any value ? 

Of what is glass composed ? 

What is silica considered to be ? 

What are the properties of its base '? 

How much potassium is requisite to decompose it ? 

Is silica soluble in alcohol, ether and oils ? 

What does silica form with fluorine ? 

What is thorina, and where found ? 

What are its characteristics ? 

How does it differ from other species of earths ? 

What is the sulphate of thorina ? 

Is it soluble in other acids ? 

How does thorina differ from zirconia ? 

What is the base of thorina ? 



CHAP. XVL 

Of Acids. 
I. Acids are the most important class of all chemical 
compounds ; they consist of a certain base, called a radi- 
cal, and an acidifier. 
14 



{ 58 INTRODUCTION 

2. The general properties of the acids are, 1. Theii 
taste is, for the most part, sour, as their name denotes ; 
and in the strongest, it is acrid and corrosive. 2. They 
generally comhine with water in every proportion, with 
a condensation of volume and evolution of heat. 3. With 
a few exceptions, they are volatilized and decomposed 
by heat. 4. They usually change the purple colours of 
vegetables to a bright red ; and 5. They appear to unite 
in definite proportions, with earths, alkalies, and metallic 
oxides, forming salts. 

3. Until within a few years, oxygen was considered 
to be the only acidifier, whence its name ; but late ex- 
periments have led some to doubt the correctness of the 
hypothesis, and to consider other substances as acidifi- 
ers. 

4. By the new nomenclature, acids are distinguished 
by the name of the base, and its degree of oxidation, or 
the quantity of oxygen it contains, by the termination of 
that name, in oxis or ic. 

Illustration. Sulphurous acid is that formed by a pro- 
portion of oxygen combined with sulphur : sulphuric, 
that which results from the combination of sulphur with 
another quantity of oxygen. 

5. Several of the radicals are capable of combining 
with a quantity of oxygen so small as not to impart to 
them the properties of acids ; in these cases they are 
converted into oxides. 

Exp. Expose sulphur to the atmosphere with a de- 
gree of heat that will not produce inflammation, it will 
absorb a quantity of oxygen, and will assume a red or 
brown colour. This is the first degree of oxygenation ; 
the second is the sulphurous acid ; the third hypo sul- 
phurous ; the fourth the sulphuric ; and if there be 



10 CHEMISTRY. 1 50 

another, it will be the super oxygenated sulphuric acid, or 
the hypo sulphuric. 

6. Some of the acids are susceptible of only one de- 
gree of oxygenation, others of two or three , there are 
very few that will admit of more. 

7. The class of acids has been distributed into three 
orders, by many chemists, viz. the mineral, vegetable 
and animal acids. But a more specific difference is now 
necessary. They have also been arranged into those 
which have a single, and those of a compound basis, or 
radical. This arrangement, however, is not only vague t 
but liable in many ether respects to considerable objec- 
tions. 

8. The chief object of classification is to give gener- 
al views to beginners in the study, by arranging together 
such substances as have analogous properties, or compo- 
sition. 

9. The number of acid substances hitherto discover- 
ed are seventy-five, and may be arranged in the follow- 
ing divisions and subdivisions. 1. Acids from inorganic 
nature, or which are procurable without having recourse 
to animal or vegetable products. 2. Acids obtained by 
means of organization. 

The first division is subdivided into three families ; 
1st. Oxygen acids. 2d. Hydrogen acids. 3d. Acids des.- 
titute of both these supposed acidifiers. 

Division 1st. — Acids from inorganic nature. 

First family — Oxygen acids. 

Section 1st, Non-metallic. 

1. Boracic. 5. Chloro-carbonous, 

2. Caibonic. 6. Nitrous. 

3. Chloric. 7. Nitric. 

4. Perchloric 8. Iodic 



169 



INTRODUCTION 



9. Hypophosphorous. 

10. Phosphorous. 

11. Phosphoric. 

12. Hyposulphurous. 



13. Sulphurous. 

14. Sulphuric. 

15. Hyposulphuric, 

16. Cyanic ? 



Section 2d, Oxygen acids. — Metallic. 

6. Columbic. 

7. Molybdic. 

8. Molybdous. 

9. Tunsfstic. 



1. Arsenic. 

2. Arsenious. 

3. Antimonious. 

4. Antimonic. 

5. Chromic. 

Second family- 

1. Fluoric. 

2. Hydriodic. 

3. Hydrochloric. 

4. Ferroprussic. 



-Hydrogen acids. 

5. Hydroprussic. 

6. Hydrosulphurous* 

7. Hydrotelkirous. 

8. Sulphuroprussic. 



Third family — Acids without oxygen or hydrogen. 

1. Chloriodic. 3. Fluoboric. 

2. Chloroprussic* 4. Fluosilicic. 



Division 2d. 

1. Aceric. 

2. Acetic. 

3. Amniotic. 

4. Benzoic. 

5. Boletic. 

6. Camphoric. 

7. Caseic. 

8. Citric. 

9. Formic. 

10. Fungic. 

11. Gallic. 

12. Kinic. 

13. Laccic. 



-Acids of organic origin. 

14. Lactic. 

15. Lampio. 

16. Lithic. 

17. Malic. 

18. Meconkv 

19. Menispermic. 

20. Margaric. 

21. Melassic, 

22. Mellitic. 

23. Moroxylic. 

24. Mucic. 

25. Oleic. 

26. Oxalic. 





TO 


CHEMISTK1 


r. 


27. 


Purpuric. 


33. 


Sebacic. 


28 


Pyrolithic. 


34. 


Suberic. 


29. 


Pyromalic. 


35. 


Succinic. 


30. 


Pyrotartaric. 


36. 


Sulphovinic ? 


31. 


Rosacic. 


37, 


Tartaric. 


32. 


Saclactic. 


33. 


Zumic. 



ten 



10. The acids of organic origin are ail decomposable 
at a red heat, and afford generally carbon, hydrogen, 
oxygen, and in some few cases, nitrogen. 

11. The acids of simple and known radicals are capa- 
ble of being decomposed by combustible bodies, to which 
they yield their oxygen. 

Exp. Drop a little sulphuric acid on a piece of bright 
iron, a black spot will be produced, which is an oxide 
formed by the oxygen of the acid, combining with the 
iron. 

12. Acid added to a compound combustible substance, 
will combine with one or more of the constituents of 
that substance, and occasion a decomposition. 

Exp. Take a dry piece of pine wood and pour upon 
it some sulphuric acid, in a short time the wood becomes 
black. 

Illustration. Wood is composed of hydrogen and car- 
bon, the oxygen of the acid combines with the hydrogen 
of the wood, to form water, and the carbon remaining, 
appears of its usual black colour. 

13. When vegetable acids are poured on wood, they 
do not produce the same effect as mineral acids, because 
their bases are composed of hydrogen and carbon ; the 
oxygen, therefore, will not easily quit the radical where 
it is already united with hydrogen. The strongest veg- 
etable acids may, perhaps, yield a little of their oxygen 
to the wood, and produce a stain^ but the carbon will 
not be sufficiently exposed to assume its black colour. 

14* 



162 INTRODUCTION 

# 

11. Mineral acids possess the power of chaining 
wood in different degrees. 

13. Boracic acid is obtained from borax, a substance 
brought from the East Indies and South America ; it is 
crjstallizable in the form of thin irregular hexagonal 
scales, of a silvery whiteness, having some resemblance 
to spermaceti. It has a sourish taste at first, and then a 
bitterish cooling one, and at last an agreeable sweetness. 
It has no smell, but when sulphuric acid is poured upon 
h^ its odour resembles that of musk. Its specific gravity 
in the form of scales is 1.479 ; after it has been fused, 
1.303. It is not altered by light. In its crystallized 
state, it is composed of 57 parts of acid, and 43 of water, 

16. The radical of the boracic acid is borcn. It is 
solid, tasteless, inodorous, and of a greenish brown col- 
our. Us specific gravity is somewhat greater than wa- 
ter. 

17. Carbonic acid is formed by the- combustion ef 
carbon, whether in the form of charcoal, or in its purest 
form oi di a m o n d . 

Exp. Light a piece of charcoal and suspend it under 
a receiver in a water bath ; after the charcoal is extin- 
guished, examine the air and it will be found to be car- 
bonic acid. 

13. Carbonic acid may be separated from the air 
with which it is mixed, by introducing into a receiver, 
containing carbonic acid, a little caustic lime or caustic 
potash, which soon attracts the whole of the carbonic 
acid to form a carbonate, the alkali is found increased in 
weight, and the volume of the air is diminished by a 
quantity equal to that of the carbonic acid which was 
mixed with it. 

19. Carbonic acid abounds in great quantities in na- 
ture, and appears to be produced in a variety of circum- 



TO CHEM1STRV. 163 

stances. It composes t Yq- of the weight of limestone, 
marble, calcareous spar, and other calcareous substan- 
ces. 

20. Water at low temperature and at common pres- 
sure, absorbs somewhat more than its bulk of fixed air, and 
then constitutes a weak acid. Heated water absorbs less ; 
if water impregnated with this acid be exposed on a 
brisk fire, the rapid escape of the gas in bubbles affordo 
an appearance as if the water were at the point of boil- 
ing, when the heat is not equal to 100°. 

21. No degree of cold has exhibited this acid in a 
condensed state of fluidity. 

22. Carbonic acid gas is emitted in large quantities 
from bodies in the state of the vinous fermentation. On 
account of its great weight, it occupies the upper part 
of the vessels in which the fermenting process- is going 
on. 

Exp. 1. Dip a lighted taper or candle into the empty 
space of a vessel, containing a liquor undergoing the vi- 
nous fermentation, it will be immediately extinguished, 
and the smoke remaining in the carbonic ackigas ren- 
ders its surface visible, which may be thrown into waves, 
by agitation, like water. 

Exp. 2. If a dish of water be immersed in this gas 
and quickly agitated, it soon becomes impregnated, and 
acquires a pungent taste. 

Exp. 3. If a candle or small animal be placed in a 
deep vessel, the former becomes extinct, and the latter 
expires in a few seconds, after the carbonic acid gas is 
poured from another vessel upon them, though the eye 
is incapable of distinguishing any thing that is poured. 

23. Carbonic acid reddens infusion of litmus ; but the 
redness vanishes on exposure to the air, as the acid flies 
off. 



164 INTRODUCTION 

24. Light, passing through carbonic acid, is refract- 
ed, but it does not effect any sensible alteration in it, 
though it appears from experiment, that it favours the 
separation of its principles by other substances. 

25. The specific gravity of carbonic acid compared 
with that of atmospheric air, is as 1.5236 to 1.0000. 

26. Water by absorbing its volume of this gas, ac- 
quires a specific gravity of 1.0015. By pressure and by 
means of forcing pumps, water may be made to absorb 
two or three times its volume of this gas. When there 
is a little soda miffed, it becomes the aerated, or 
soda water of the shops. 100 cubic inches of oxygen 
weighs 33.8 grs. and 100 cubic inches of carbonic acid, 
46.5 grs. ; hence the weight of combined charcoal in 
100 cubic inches of carbonic acid is 12.7 grs. 

27. Carbonic acid unites with the alkalies, earths, and 
some of the metallic oxides,forming salts called carbonates, 
which possess peculiar properties* 

28. Carbonates are composed either of one prime of 
the acid, and one of the base, or of two of the acid and 
one of the base ; the former are called carbonates, the 
latter bi-carbonates. 

29. Carbonic acid gas is not respirable, yet it is 
formed in the lungs ; so that the air which we expire, al- 
ways contains a certain proportion of carbonic acid, 
which is much greater than that which is found com- 
monly in the atmosphere. 

Exp. Prepare some lime water, and breath into it 
through a tube or pipe, the water immediately becomes 
turbid in consequence of the union of the lime with the 
carbonic acid of the lungs. 



TO CHEMISTRY, 165 

PRACTICAL QUESTIONS. 

Of what do acids consist ? 

What are the general properties of the acids ? 

Is oxygen the only acidifier ? 

How are acids distinguished by the new nomencla- 
ture ? 

Illustrate it. 

Suppose the oxygen should not produce an acid, what 
would you call it ? 

Of how many degrees of oxygenation are the acids 
capable ? 

How are the class of acids distributed ? 

What is the object of classification ? 

What are the number of acids ? 

Name the acids. 

How are the acids of organic origin decomposable ? 

How are acids of simple and known radicals decom- 
posable ? 

Illustrate by experiment. 

Why does sulphuric acid turn wood black ? 

Why do not vegetable acids produce the same effect ? 

Do mineral acids possess the power of charring wood 
equally ? 

What is boracic acid, its specific gravity and proper- 
ties ? 

What is its base ? 

How is carbonic acid formed ? 

How do you form it in experiment ? 

How can you separate carbonic acid from the air with 
which it is mixed ? 

Where is carbonic acid found ? 

What effect has water upon it ? 

Can it be condensed into fluidity ? 

Is it emitted from vinous fermentation ? 



166 INTRODUCTION 

Prove it by experiment. 
Has it any effect on vegetable colours ?' 
What effect has it on light ? 
What is its specific gravity ? 

What specific gravity does water acquire by absorbing 
this gas ? 

With what does carbonic acid unite ? 
What are carbonates and bi-carbonates ? 
Is this gas respirable ? 



CHAP. XVII. 

Continuation of Acids* 
i . Muriatic acid is that obtained from sea salt, Muri- 
ate of soda, by distillation with sulphuric acid. It is pro- 
cured in the form of gas and absorbed in water. 

2. When this gas is received in glass jars over mer- 
cury, it is invisible and possesses all the mechanical prop- 
erties of air. Its odour is pungent and peculiar. Its. 
taste acrid and corrosive. It will not support respira- 
tion or combustion, is changed in bulk by alteration of 
temperature. 

Exp. Fill a jar with the gas and immerse in it a 
lighted taper, it is immediately extinguished. 

3. Muriatic gas consists of chlorine and hydrogen 
united in equal volumes, and by the new nomenclature, 
called hydro chloric acid. 

Exp. When potassium, tin or zinc, is heated in con* 
tact with this gas over mercury, one half of the volume 
disappears, the remainder is found to be pure hydrogen, 
#od the solid residue is found to be a metallic chloride. 



>T0 CHEMISTRY. J67 

4. Muriatic acid gas has a very strong afpnity for wa- 
ter, as is evident, from its forming a white cloud in con- 
tact with the atmosphere, which proceeds from its com- 
bination with aqueous vapour. 

5. The solution of this gas is commonly of a pale 
yellow colour ; it may be rendered colourless by repeat- 
ed distillations. 

6. The cause of the colour is not known. 

7. Its specific gravity as commonly obtained, is about 
1.170, in which state it contains about 25 per cent of dry 
acid. 

8. No liquid acid appears capable of existing when 
the proportion of gas is much more than four or five 
hundred times the volume of water employed in its 
preparation. At this strength, it appears to contain 
about 48 per cent of the acid gas. Its specific gravity 
is 1.5, and its boiling point 60°. 

9. Its boiling point gradually lessens with a less pro- 
portion of gas, till it arrives at 12 per cent of gas, when 
it boils at 232°. 

10. When the acid gas is in greater proportion than 
12 per cent, the gas escapes until it arrives at that stand- 
ard ; and when in a less proportion, the water escapes, 
to reduce it to the same standard. 

11. Muriatic acid combines with earths, alkalies, and 
metallic oxides, forming substances called muriates, 

12. Muriates, when in a state of dryness, are chlo- 
rides, being a combination of the base with the chlorine 
of the acid, but the least moisture causes them to pass to 
the state of muriates or hydrochlorides. Chlorides, prop- 
erly speaking, contain neither an acid nor an alkali. 

13. Chloric acid has the same base as muriatic, name* 
lj| chlorine. 



168 INTRODUCTION 

Exp. When a current of chlorine is passed for some 
time through a solution of barytic earth in warm water, 
a substance called hyperoxymuriate of barytes is formed 
as well as some common muriate. The latter is sepa- 
rated by boiling some phosphate of silver in the com- 
pound solution. The former may then be obtained by 
evaporation in fine rhomboidal prisms. When a few 
drops of sulphuric acid diluted is added, the liquid be- 
comes sensibly acid. By continuing to add sulphuric 
acid with caution, an acid liquid entirely free from sul- 
phuric acid which has united with the barytes, will be 
obtained, which is chloric acid dissolved in water. 

14. its properties are ; it has no sensible smell. Its 
solution in water is perfectly colourless. Its taste is very 
acid, and it reddens litmus without destroying the colour. 
It produces no alteration on solution of indigo in -sulphu- 
ric acid. Light does not decompose it. It may be kept 
a long time exposed to the air, without sensible diminu- 
tion. W T hen concentrated, it has something of an eiry 
consistence. When exposed to heat, it is partly decom- 
posed into oxygen and chlorine, and partly volatilized 
without alteration. 

15. Chloric acid is decomposed by muriatic, sulphu- 
rous acid, and sulphuretted hydrogen. Combined with 
ammonia, it forms a fulminating salt. It does not pre- 
cipitate any metallic solution. It readily dissolves zinc, 
disengaging hydrogen ; but it acts slowly on mercury. 

16. Chloric ac id forms salts with the alkalies and earths, 
called chlorates, or hyperoxymuriates. 

17. Perchloric acid is procured by pouring three 
parts of sulphuric acid on one of chlorate of potash in a 
retort, perchlorate of potash will be obtained, and by 
adding sulphuric acid, at 280° perchloric acid is produced. 



TO CHEMISTRY, 169 

It seems to consist of 7 parts of oxygen, combined with 1 
of chlorine, or 7.0 + 4.45. 

1 8. Chloro carbonous acid is composed of chlorine and 
protoxide of carbon. 

Observation. Experiments made by Dr. John Davy, 
go to prove that chlorine and carbonic oxide unite rap- 
idly, when exposed to the direct solar beams, and one 
volume of each is condensed into one volume of the com- 
pound. The resulting gas possesses very peculiar prop- 
erties, approaching to those of an acid. From the pe- 
culiar influence of the sun beams in effecting this combi- 
nation, Dr. Davy called it phosgene gas. 

19. Its properties are ; it does net fume in the at- 
mosphere. Its odour is different from that of chlorine. 
It affects the eyes in a peculiar manner, producing a 
rapid flow of tears, and occasioning painful sensations. — 
It reddens dry litmus paper ; and condenses four volumes 
of ammonia into a white salt, while heat is evolved, — 
Neither sulphur, phosphorus, oxygen, nor hydrogen, 
though aided by heat, produce any change on the acid 
gas ; but oxygen and hydrogen together, in due propor- 
tion, explode in it. On exposure to water, it is convert- 
ed into muriatic and carbonic acid gases. 

20. According to Thenard, chloro carbonous acid is 
a compound of muriatic and carbonic acids, resulting 
from the mutual actions of the oxy muriatic acid and car- 
bonic oxide. 

21. Nitrous acid was formerly called fuming nitrous 
acid. It is in the form of an orange coloured liquid. It 
is so volatile as to boil at the heat of 82°. 

22. Its specific gravity is 1.450. 

23. When mixed with water it is decomposed, and- 
nitrous gas is disengaged, with effervescence, 

15 



170 INTRODUCTION 

24. It is composed of one volume of oxygen, united 
with two of nitrous gas. It appears to form a distinct 
genus of salts, called nitrites. 

25. Nitric acid is composed of oxygen and nitrogen, 
which are the constituents of the atmosphere, and differs 
in nothing from the air we breathe, except in the pro- 
portion of the ingredients, and in their complete chemi- 
cal union. 

Exp. 1. Mix the two gases in a glass tube, and pass 
through them a number of electric explosions, the gases 
w r ill combine, and nitric acid will be formed about the 
inside of the tube. This method of proving the compo- 
sition, is called the synthetic. 

Exp. 2. Place a porcelain tube across a furnace, and 
adjust the apparatus as in the decomposition of water, 
when the tube becomes red hot, pass the acid through 
it, it will be found to consist of nitrogen and oxygen 
gases. This method is called the analytical method of 
proving it. 

23. This acid contains a large proportion of oxygen, 
but retains it w T ith very little force. It is therefore very 
corrosive, and destroys, or burns, all kinds of organized 
matter. 

Exp. Take strong nitric acid and pour a few drops 
into a glass, containing oil of turpentine, a violent in- 
flammation immediately ensues. This experiment suc- 
ceeds best when a little sulphuric acid is added with the 
nitric. 

27. The properties of nitric acid are ; it is clear and 
colourless, like water. Its smell pungent. Its taste ex- 
ceedingly acid, and it imparts a yellow stain lo the skin. 

28, Nitric acid dissolves or oxidates almost all met- 
als in consequence of the facility with which it parts 
with its oxvsyen. 



TO CHEMIST11V. 171 

29. Nitric acid is generally obtained from nitre, or 
salt petre, by distillation with sulphuric acid. When di- 
luted, it is called aquafortis. Nitric acid combines with 
alkalies, earths and metallic oxides, forming- a genus of 
salts called nitrates. 

30. Iodic acid is obtained from the action of sulphu- 
ric acid on the iodate of barytes, made by causing bary- 
tic water to act on iodine. 

31. Iodic acid, when pure, has a strong acid astrin- 
gent taste, but no smell. Its density is considerably 
greater than that of sulphuric acid. It melts, and is de- 
composed into iodine and oxygen, at a temperature of 
about 620°. It consists of 15.5 iodine, 5. oxygen. 

32. Iodic acid deliquesces in the air, and is very solu- 
ble in water. It first reddens, and then destroys the blues 
of vegetable infusions. It blanches other vegetable col- 
ours. It appears to form combinations with all the fluid 
or solid acids, which it does not decompose. 

33. Hypophosphorous acid is obtained from the phcs- 
phuret of barytes, by means of sulphuric acid. 

34. It has a very sour taste > reddens vegetable blues, 
and does not crystallize. The hypophosphites have the 
property of being all soluble in water. The hypophos- 
phorous acid is probably composed of 2 primes of phos- 
phorus =r 3. + 1 of oxygen. 

35. Phosphorous acid is obtained from the action of 
phosphorus and corrosive sublimate, in an elevated tem- 
perature. In a liquid state it consists of 80.7 acid -f- 19.3 
water. Its prime equivalent is 2.5. 

36. It has a very sour taste, reddens vegetable blues, 
and forms salts with the salifiable bases. When heated 
strongly in open vessels, it inflames, phosphuretted hy- 
drogen is evolved, and phosphoric acid remains? 



fT2 ^TROje^!.GTION 

37. Phosphoric acid abounds in the mineral, vegeta^ 
ble and animal kingdoms. 

38. Its general characters are ; it is soluble in water 
in all proportions. It produces heat when mixed with 
water. When pure, it has no smell, its taste is sour, but 
not corrosive. When perfectly dry it sublimes in close 
vessels. When considerably diluted with water and 
evaporated, the aqueous vapour carries up a small por- 
tion of the acid. With charcoal or inflammable matter, 
in a strong heat, it loses its oxygen and becomes con- 
verted into phosphorus. Its composition appears to be 
100 phosphorus + 134.5 oxygen, whence its equivalent 
is 3.500. 

39. Phosphoric acid for general purposes is extract 
ed from bones, which are phosphate of lime ; when cal- 
cined, sulphuric acid is added to them in powder, a de- 
composition ensues, sulphuric acid combines with the 
lime, and the phosphoric acid is set at liberty. 

40. Hyposuiphurous acid has been obtained from a 
class of salts, formed by an acid of sulphur, having a 
proportion of oxygen less than that of sulphurous acid. 

Observation. Mr. Herschel mixed a diluted solution of 
hyposulphite of strontites, with a slight excess of diluted 
sulphuric acid, and after agitation, poured the mixture on 
three filtres. The first was received into a solution of 
carbonate of potash, from which it expelled carbonic 
acid gas. The second portion being received succes- 
sively into nitrates of silver and mercury, precipitated 
the metals copiously in the state of sulphurets, but pro- 
duced no effect on solutions of copper, iron or zinc. — 
The third, being tasted, was acid, astringent and bitter, 
When fresh filtered, it was clear, but became milky on 
standing, depositing sulphur, and coloured sulphuric acid, 
A moderate exposure U> air or heat 3 caused its entire 



TO CHEMISTRY. 173 

decomposition. The prime equivalent of this acid is 
found to be 59.25. it is composed of 20 sulphur -f 10 
oxygen* 

41. Hyposulphurous acid unites with alkalies and 
earths, forming compounds called hyposulphites. 

42. Hyposulphuric acid is obtained by passing sulphu- 
rous acid gas over the black oxide of manganese ; a com- 
bination takes place, the excess of the oxide of manga- 
nese is separated by dissolving the hyposulphate of man- 
ganese in water. Caustic barytes precipitates the man- 
ganese and forms with the new acid a very soluble salt, 
which freed from the excess of barytes by a current of 
carbonic acid, crystallizes regularly. To this salt in so- 
lution, sulphuric acid is cautiously added, which throws 
down the barytes, and leaves the hyposulphuric acid in 
the water. 

43. It has the following properties. It is decompos- 
ed by heat into sulphurous and sulphuric acids. It forms 
soluble salts with strontites, barytes, lime, lead and sil- 
ver. The hypcsulphates yield sulphurous acid, when 
their solutions are mixed with acids, if the mixture be- 
comes hot of itself or by artificial heat. They disengage 
a large quantity of sulphurous acid at an high tempera- 
ture, and are converted into neutral sulphates. It is 
composed of 8 sulphur ~f- 10 oxygen. 

44. Sulphurous acid may be obtained by heating sul- 
phuric acid with mercury, or bits of copper in a glass 
retort. 

Exp. Put two parts of sulphuric acid and one of mer- 
cury into a glass retort, and apply to it the heat of an - 
Argand's lamp, the mixture effervesces, and throws off a 
gas, which should be received over mercury, this gas is_~ 
sulphurous acid. 
15* 



174 INTRODUCTION 

45. Sulphurous acid in a state of gas is colourless anft 
invisible. It is incapable of maintaining combustion, 
and deleterious to animal life. It possesses a strong suf- 
focating odour ; 100 cubic inches weigh about 68 grains. 
Its specific gravity, when compared with hydrogen, is as 
30. to 1 . It whitens many animal and vegetable sub- 
stances. 

46. Water at 61° absorbs 33 times its volume, and 
when saturated, acquires the specific gravity of 1.6513 
at 6S°. • 

47. It is decomposed by hydrogen, carbon, and sul- 
phuretted Irydrogen gas, when assisted by heat. It oxi- 
dizes iron and zinc. 

48. It consists of sulphur 68 

Oxygen 32 



100 

49. Sulphuric acid so named from its being prepared 
from sulphur, has been long known by the name of oil 
of vitriol, from its oily appearance, and vitriolic acid 
from its being first prepared from iron. 

50. Sulphuric acid has a strong affinity for water, 
and when combined with it, which is the state we meet 
within it, is properly an hydro sulphuric. 

51. It is composed of sulphur, oxygen and water, and 
when good, its specific gravity should be 1.8485. 

52. It is slightly viscid, transparent and colourless ; 
destitute of smell, of a strong acid taste. When diluted 
with an equal weight of water,it freezes at — 38° F. and 
boils at 580°. It absorbs water rapidly from the atmos- 
phere. When water is mixed with it, the temperature 
is suddenly increased. 

Exp. Take a small quantity of water in one glass, 
and about twice as much by measure of sulphuric acid in 



TO CHEMISTRY. 175 

another, let them both be of the common temperature 
of the atmosphere ; suddenly mix them, and the heat 
will be increased to the boiling point of water. 

Illustration The bulk of the two bodies when mixed 
is less than when they were in a separate state ; this ac- 
counts for the sudden extrication of caloric. 

53. Diluted acid having a specific gravity of 1.6321, 
has suffered the greatest condensation ; 100 parts in bulk 
have become 92.14. If either more or less acid exist in 
the compound, the volume will be increased. The 
cause of the maximum condensation at this particular 
point of dilution is unknown. 

54. Sulphuric acid is decomposed, when mixed with 
inflammable bodies. 

Exp. I . If a piece of charcoal made red hot be im- 
mersed in common concentrated sulphuric acid, the acid 
will be decomposed and part of its oxygen is attracted 
by the charcoal forming carbonic acid, while part of the 
acid goes off in thick white fumes. 

Exp. 2. Phosphorus, with the aid of heat, decom- 
poses the sulphuric acid by absorbing a part of its oxy- 
gen. 

Exp. 3. Immerse bits of straw in this acid, they be- 
come black. 

Illustration. Vegetables are composed of carbon, hy- 
jdrogen and oxygen ; the hydrogen of the vegetable com- 
bines with the oxygen of the acid, and leaves the straw 
in a carbonized state. 

55. Sulphuric acid decomposes water, and the hy- 
drogen gas is evolved. 

Exp. Pour sulphuric acid diluted with water on some 
filings of iron or zinc, a violent action takes place ; the 
hydrogen of the water is disengaged in the form of gas f 



1*76 LVIRODICTICKN 

while the oxygen combines with the metal and forms an 
oxide. 

56. Sulphuric acid does not oxidize gold, platinum, 
tungsten, or titanium. 

57. Sulphuric acid unites with all the alkalies and 
earths, except silica, and with many of the metallic ox- 
ides, forming a peculiar kind of salts, called sulphates. 

58. Sulphuric acid, in its concentrated state, consists, 
in 100 parts, of 30 sulphur, 45 oxygen, 25 water. 

59. It is employed in a variety of manufactures, in 
dyeing ; in medicine and pharmacy ; and is therefore of 
considerable importance. 

60. Cyanic acid, hydrocyanic acid, is usually called 
prussic acid, and is an acid obtained from the beautiful 
blue pigment, called Prussian blue, whi^h is a com- 
pound of prussic acid with iron and alumina. 

Exp. To a quantity of powdered prussian blue dif- 
fused in boiling water, let red oxide of mercury be aJ- 
ed in successive portions, until the blue colour is de- 
stroyed. Filter the liquid and concentrate by evapora- 
tion, until a pellicle appears. On cooling, crystals of 
prussiate or cyanide of mercury will be formed. Dry 
these and put them into a tubulated glass retort, to the 
beak of which, is adopted a horizontal tube, about, twa, 
feet long and fully half an inch wide a*, its middle part. 
The first third part of the tube next the retort is filled 
with small pieces of white marble, the two other thirds 
with fused muriate of lime. To the end of this tube is 
adopted a small receiver, which should be immersed in 
ice. Pnur on the crystals, muriatic acid, in rather less 
quantity than is sufficient to saturate the oxide of mer- 
cury which formed them. Apply a very gentle heat to 
the retort. Hydrocyanic acid will be evolved in vapour > 
and will condense in the tube. If muriatic acid passes 



TO CHEMISTRY. \ 179 

over, it will be obstructed by the marble, while the wa- 
ter will be absorbed by the muriate of lime. By means 
of a moderate heat applied to the tube, the acid may be 
made to pass successively along, and after being left- 
sometime in contact with muriate of lime, it may be, 
finally, driven into the receiver. As the carbonic acid 
evolved from the marble by the muriatic is apt to carry 
off some of the prussic acid, care should be taken in con- 
ducting the distillation. 

Gl. Prussic acid is a colourless liquid, possessing a 
strong odour of peach blossoms ; when snuffed up the 
nose, it may produce sickness, or fainting. Its taste is 
cooling at first, then hot, and operates as a most virulent 
poison, producing almost instant death on animals. Its 
specific gravity at 44|° is 0.7058 ; at 64° it is 0.6969.— 
It boils at 81|° and congeals at about 3°. It then crys- 
tallizes regularly, sometimes in the fibrous form of ni- 
trate of ammonia. The cold which it produces, when 
reduced to vapour, even at the temperature of 68°, is 
sufficient to congeal it. 

Exp. Put a small drop on a piece of glass tube or 
glip of paper, it will become solid. 

62. The specific gravity of its vapour, experimentally 
compared, to that of air, is 0.9476 to 1.0000. By calcu- 
lation from its constituents, it is 0.9360. 

63. The small density of prussic acid compared with 
its great volatility, furnishes a proof that the density of 
vapours does not depend upon the boiling point of the 
liquids that furnish them, but upon their peculiar con- 
stitution. 

64. This acid, when procured for experiment or me- 
dicinal purposes, must be made use of as soon as possi- 
ble, as it cannot be preserved, even in close stopped 
phials, for any length of time, without decomposition. 



178 INTRODUCTION 

65. Prussia acid has a strong affinity for metallic ox- 
ides, and precipitates the solution of iron m acids, of a 
blue colour, which is called Prussian blue. 

66. To form Prussian blue, the peroxide of iron 
should be used, as the protoxide produces a pale blue 
colour, which will not be deep or permanent, unless ex- 
posed for some time to the air, whence it imbibes oxy- 
gen. 

Exp. Take a solution of green sulphate of iron, and 
add to it a solution of prussiate of potash, a dirty green 
precipitate will be formed, which, on exposure to the 
air, assumes a pale blue colour. If we now pour nitrous 
acid upon it, the Prussian blue colour will be immedi- 
ately produced, as the acid yields its oxygen to the pre- 
cipitate. 

67. Prussic acid is composed of hydrogen, nitrogen 
and carbon ; not a trace of oxygen has ever been found 
in it. 

PRACTICAL QUESTIONS. 

What is muriatic acid ? 
What are the properties of the gas ? 
Of what does it consist ? 
Has it any affinity for water ? 
What is the colour of a solution of this gas ? 
What is the cause of the colour ? 
What is its specific gravity ? 
When is the liquid acid capable of existing ? 
When it contains 48 per cent of the acid gas, what is 
its specific gravity ? 

What is its boiling point ? 

What phenomena attend the boiling of this acid • 

With what does it combine and form ? 

What are muriates 7 



TO CHEMISTRY. 179 

What is chloric acid ? 

How do you form it ? 

What are its properties ? 

How is it decomposed ? 

What does it form with the alkalies and earths ? 

How is perchloric acid obtained ? 

Of what is chloro-carbonous acid compos 

What are its properties ? 

W^hat is the opinion of Thenard with regard to its 
composition ? 

What is nitrous acid ? 

Of what is it composed ? 

Of what is nitric acid composed ? 

How do you prove it synthetically and analytically ? 
What is the cause of its corrosive and burning quality ? 

W r hat are the properties of nitric acid ? 
Why does it oxidate metals ? 

How is it obtained ? ■ ~ 

What does it form with earths and alkalies ? 
How is iodic acid obtained ? 
What are its properties ? 

What effect does the air and water have upon it, and 
how does it effect vegetable colours ? 
How is hypophosphorous acid obtained ? 
What are its properties ? 
How is phosphorous acid obtained ? 
What are its properties ? 
W r here is phosphoric acid found ? 
What are its characters? 
How is it obtained ? 
How is hyposulphurous acid obtained ? 
How did Mr. Herschell obtain it ? 
Does it unite with salifiable bases ? 
How is hyposulphuric acid obtained ? 



180 INTRODUCTION 

What are its properties ? 

How can sulphurous acid be obtained ? 

What are its properties ? 

How much will water absorb ? 

What will decompose it ? 

Of what does it consist ? 

What is sulphuric acid ? 

Has sulphuric acid any affinity for water ? 

Of what is it composed ? 

What are its properties ? 

Why is caloric extricated when this acid is mixed with 
water ? 

Why does it turn wood black ? 

When added in a diluted state to iron filings, what is 
decomposed ? 

What does it form with the alkalies, earths and metal- 
lic oxides ? 

Of what does it consist ? 

Is it much used ? 

What is cyanic acid, or hydrocyanic acid ? 

How do you form it ? 

What are its characteristics ? 

What is the specific gravity of its vapour ? 

What proof does its small density furnish ? 

Is it easily decomposed ? 

Has it any affinity for metallic oxides ? 

What should be used to form Prussian blue I 

Of what is it composed ? 



TO CHEMISTRY, 181 



CHAP. XVIII. 

Of Oxygen Acids — Metallic* 

1. Arsenic acid is formed from a metal called arse- 
nic. 

2. It is obtained from the white substance called arse- 
nic of the shops-, which is the oxide of arsenic, by heat- 
ing it with nitric acid. 

3. It does not crystallize, but attracts the moisture of 
the air, has a sharp caustic taste, reddens blue vegeta- 
ble colours, is fixed in the fire, and is a violent poison. 
Its specific gravity is 3.391. It appears to consist of 100 
metal, and from 5£ to 53 oxygen. 

4. Combustible substances decompose this acid. 
Exp. If two parts of arsenic acid be mixed with one 

of charcoal, the mixture introduced into a glass retort, 
coated, and a matrass adopted to it, and the retort then 
gradually heated in a reverberatory furnace till the bot- 
tom is red ; the mass will be violently inflamed, and the 
acid reduced and rise to the neck of the retort in the 
metallic state, mixed with a little oxide and charcoal 
powder; a few drops of water will be found in the re- 
ceiver. 

5. The arsenic acid combines with the earthy and al- 
kaline bases, forming salts, called arseniates ; they are 
decomposable by charcoal, which separates the arsenic 
from them by means of heat. 

6. Arsenic acid does not act on gold or platinum, nor 
on mercury or silver, without the aid of a strong heat ; 
but it oxidizes copper, iron, lead, tin, zinc, bismuth* an- 
timony, cobalt, nickel, manganese, and arsenic. 

7. Arsenious acid is the white arsenic of the shops^ 

which is a compound of the metal with oxygen. 
1§ 



132 INTRODUCTION 

8. It is a most virulent poison. It reddens some of 
the blue vegetable colours, and turns the syruip of violets 
green. When thrown on burning* coals, it emits white 
fumes, winch have a strong smell of garlic. It is acted 
upon by hydrogen and carbon, which deprive it of its 
oxygen at a red heat, and reduce the metal ; the former , 
forming water, the latter carbonic acid, with the oxy- 
gen. 

9. Its specific gravity is 3.7. It is composed of metal 
9.5. oxygen -\~ 3. Its prime equivalent is 12.5. 

10. It is soluble in thirteen times its weight of boil- 
ing water, but requires eight} 7 times its weight of cold. 

Exp. When a mixture of arsenious acid with quick- 
lime is heated in a glass tube, at a certain temperature, 
ignition suddenly pervades the whole mass, and jnetallic 
arsenic sublimes. As arseniate of lime is found at the 
bottom of the tube, we infer that a portion of the arse- 
nious acid is robbed of its oxygen to complete the acidi- 
fication of the rest. 

1 1. Arsenious acid is used in numerous instances in 
the arts, and some in medicine. It has lately been used 
as an alterative, with advantage, in chronic rheumatism. 

12. Antimonious acid is obtained from the metal of 
that name, and is the tritoxide, or third degree of oxy- 
genation of the metal, by immediate combustion. It was 
formerly called, from its white appearance, argentine 

Jlowers of antimony. It may also be formed by digesting 
hot nitric acid on the metal. 

13. Antimonious acid when fused with one fourth of 
antimony, loses one portion of its oxygen, and is con- 
verted into the deutoxide of antimony. 

14. Antimonious acid forms salts with different bases, 
called antimonltes. 



TO CHEMISTRY. \&$ 

IS. It consists of 78.6 antimony, and -f- 21.4 oxygon. 

1G. Antimonic acid is the peroxide of antimony. 

17. It is formed when the metal in powder is ignited 
with six times its weight of nitre in a silver crucible. — 
The excess of potash and nitre being afterwards sepa- 
rated with hot water, the antimoniate of potash is ihen 
to be decomposed by muriatic acid, when the antimonic 
acid, of a straw colour, will be obtained. 

lo. It is insoluble in water, but reddens vegetable 
blues. It does not combine with acids. At a red heat, 
oxygen is disengaged, and antimonious acid is produced. 

19. Chromic acid has been obtained from the chrc- 
mate of lead, or the red lead ore of Siberia, and from 
the chromate of iron, an abundance of which, exists near 
Baltimore, in Maryland. The acid is the tritoxide of 
chrome. 

SQL It is soluble in water, and crystallizes by cooling 
and evaporation, in long prisms of a ruby red. Its taste 
is acrid and styptic. Its specific gravity is not exactly 
known, but it always exceeds that of water. It power- 
filly reddens the tincture of turnsole. 

2U The chromic acid readily unites with alkalies, 
and is the only acid that has the property of colouring 
its salts. The salts are called chrcmates. 

22. Chromic acid causes different coloured precipi- 
tates with the metallic oxides. 

Exp. 1. Precipitate mercury from its solution in ni- 
tric acid, by chromic acid, a dark cinnabar coloured sub- 
stance will be thrown down. 

Exp. 2. Add chromic acid to a solution of nitrate of 
silver, a precipitate is formed, which, at first is of a 
beautiful carmine, but becomes purple by exposure to 
light. 



184 INTRODUCTION 

Exp. 3. With nitrate of copper, it gives a chesnut 
red precipitate. 

Exp. 4. With solutions of sulphate of zinc, muriate 
of bismuth, muriate of antimony, nitrate of nickel, and 
Jnuriate of platina, chromic acid produces yellowish pre- 
cipitates. 

Exp. 5. With muriate of gold, it produces a greenish 
precipitate. 

Exp. 6. If paper be impregnated with the acid and 
exposed to the sun a few days, it assumes a green col- 
our, which remains permanent in the dark. 

23. Columbic acid is an acid obtained from a metal 
called columbium, or tantalium, or yttro-tantalite. 

24. It is in the form of a white powder, which is in- 
soluble in nitric and sulphuric acids, but partially in mu- 
riatic. 

25. It forms with barytes an insoluble salt. Its pro- 
portions are inferred to be 100 metal, and 5.485 oxy- 
gen. 

26. Molybdic acid is a substance obtained from the 
metal, called Molybdenum. 

27. It changes vegetable blues to red ; unites with 
the alkalies, forming salts, called molybdates, and pre- 
cipitates the metals from their solutions. Its specific 
gravity is 3.460 ; and its prime equivalent is 9, consisting 
of 3 of oxygen + 6 of metal. 

28. Molybdous acid is the deutoxide of molybdenum. 
It is of a blue colour, and possesses acid properties. It 
reddens vegetable blues, and forms salts with the bases. 

29. Air or water when left to act sometime on the 
metal, convert it into this acid. 

30. It consists of 100 metal, and 34 oxygen, nearly. 

31. Tungstic acid has been found only in two mine- 
rals, the one formerly called tungsten, tungstate of lime^ 



fO CHEMISTRY. 185 

the other is composed of tungstic aci^, oxide of iron, 
and a little oxide of manganese, called Wolfram. 

32. The tungstic acid is tasteless and does not redden 
vegetable blues. It unites and forms salts with the bases, 
such as earths, alkalies, and metallic oxides. 

33. It is composed of 100 parts metallic tungsten, 
and 2.5, or 26.4 oxygen. 

PRACTICAL QUESTIONS. 
How is arsenic acid obtained ? 
What are its properties ? 

What effect have combustible substances on this acid ? 
With what does it combine ? 
Does it act on the metals ? 
What is arsenious acid ? 
What are its properties ? 
What is its specific gravity ? 
What is its solubility ? 
Is arsenious acid of much use ? 
How is antimonious acid obtained ? 
What phenomena does it exhibit when fused $ 
What does it form ? 
Of what does it consist ? 
What is antimonic acid ? 
How is it formed ? 
What are its properties ? 
Of what is it composed ? 
From what has chromic acid been obtained ? 
What are its properties ? 
Does it unite with alkalies ? 
What effect does it have on metallic oxides ? 
What is eelumbic acid ? 
What are its characteristics ? 
What is molybdic acid ? 
IS* 



136 INTRODUCTION 

What are its characteristics ? 

What is molybdous acid ? 

What effect have air and water on the metal I 

Of what does it consist ? 

Where has tungstic acid been found ? 

What are its characteristics ? 

Of what ie it composed ? 



CHAP. XIX. 

Continuation of Acids. — Hydrogen Acids. 

1. Fluoric acid is obtained from the fluate of lime, 
known by the name of Derbyshire spar, or flaor spar, a 
name acquired from the circumstance of its being used 
to render the ores of metals more fluid, when fused. 

2. The spar has been long known, and in use for a 
\ariety of ornamental and other purposes ; but its real 
nature was not ascertained until Scheele discovered that 
it consisted of lime, united with a peculiar acid, which 
has obtained the name of fluoric acid. 

3. It may be prepared hy placing powdered fluor 
«par in a retort of lead or silver, with a receiver of the 
same metal adopted, if its weight of sulphuric acid be 
then poured upon it, the fluoric acid will be disengaged 
hy the application of a moderate heat. 

4. This acid gas readily combines with water, for 
which purpose it is necessary that the receiver should 
be half filled with that fluid. 

5. When the receiver is surrounded with pounded 
ice* and no water put into it, the acid condensed is an in- 
teniely active fluid. It has the appearance of sulphuric 



TO CHEMISTRY. J87 

acid, but i3 much more volatile, and emits white fumes 
when exposed to the air. Its specific gravity is only. 
1.0000. When applied to the skin, it instantly corrodes 
it, and produces wounds very difficult to heal. When 
potassium is introduced into it, it acts with intense ener- 
gy, and produces hydrogen gas and a neutral salt. When 
lime is made to act upon it, a violent heat is excited, 
water is formed, and the same substance as fluor spar is 
produced. With water in a certain proportion, its densi- 
ty is increased to 1.25. When it is dropped into water, 
a hissing noise is perceived, with much heat, and an acid 
fluid, not disagreeable to the test;, is formed, if the wa- 
ter be in sufficient quantity. It instantly corrodes and 
dissolves glass, in consequence of its great affinity for 
silex. 

Exp. Coat a piece of common window glass with 
wax, and then with a pin draw any figures on it you 
please, by scratching the wax through to the glass ; pour 
over it fluoric acid, and it will corrode the glass only 
where the wax has been removed, and produce a repre- 
sentation similar to an engraving. Or the glass may be 
placed on a cup containing the sulphuric acid and fiuor 
spar ; the cup placed in a temperature of 212°, the gas 
which arises will corrode equally as well as the liquid 
acid. 

6. Fluoric acid is regarded as a compound of hydro* 
gen, arcd a principle which acts the part of an acidifier, 
and which is found only in thefluates, called fluorine. 

7. Hydr iodic acid resembles the muriatic in being 
gaseous in its insulated state. 

8. It may be prepared in the following manner. — 
Mix 4 parts of iodine with one of phosphorus, in a small 
glass retort, apply a gentle heat, and add a few drops of 
water from time to time, a gas comes over, which must 



18$ INTRODUCTION 

be received over mercury ; or it may be condensed with 
water in the same manner as muriatic acid. 

9. In the state of gas, its specific gravity is 4.4 ; 1G0 
cubic inches weigh 134.2 grains. It is elastic and invisi- 
ble, but has a smell somewhat similar to muriatic acid. 
It is composed of iodine and hydrogen, by weight 8.6 L 
iodine, 0.0694 hydrogen. 

10. Hydriodic acid is paitly decomposed at a red 
heat, and its decomposition is complete ; if oxygen be 
present, water is formed, and iodine separated. 

11. Ferroprussic acid is obtained in the following 
manner. Into a solution of what is usually called prus- 
siate of potash, pour hydrosulphuret of barytes as long as 
any preceipitate forms. Throw the whole on a nitre,., 
and wash it with cold water. Dry it, and having dis- 
solved 100 parts in cold water, add gradually 30 of con- 
centrated sulphuric acid, agitate the mixture, and set it 
aside until the liquor becomes clear ; this is ferroprussic 
acid, or ferruretted chyazic acid. 

12. It has a pale lemon yellow colour, but no smell. 
Heat and light decompose it. Hydrocyanic acid is then 
formed, and white ferroprussiate of iron, which soon be- 
comes blue. 

13. Its affinity for the salifiable bases enables it to 
displace acetic acid without heat from the acetates, and 
to form ferroprussiates. 

14. The base of this acid is prussine, or that which 
generates blue, which is united to hydrogen as its acidi- 
fier. 

15. Hydromlphurous acid is sulphurous acid combined 
with hydrogen. 

16. Hydrotelluric acid is a combination of tellurium 
with hydrogen. It combines with the alkalies. Its smell 
is very strong and peculiar. 



TO CHEMISTRY. 189 

^17. Sulphuroprussic acid, or sulphuretted chyazic acid 
is a transparent and colourless liquid, possessing a strong 
odour, somewhat resembling acetic acid. Its specific 
gravity is 1.022. It dissolves a little sulphur at a boil- 
ing heat, it then blackens nitrate of silver, but the pure 
acid throws down the silver white. By repeated distil- 
lations, the sulphur is separated, and the acid decompos- 
ed. 

1 S. It combines with the earths and alkalies, and 
forms salts, called sulphuroprussiates, 

ACIDS WITHOUT OXYGEN OR HYDROGEN. 

19. Chloriodic acid was formed, by Sir H. Davy, by 
admitting chlorine in excess to known quantities of io- 
dine, in vessels exhausted of air, and repeatedly heating 
the sublimate. Operating in this way, he found that io- 
dine absorbed less than one third of its weight of chlo* 
rine. 

20. It is of a bright yellow colour ; wheo fused, it 
becomes of a deep orange, and when rendered elastic, 
it forms a deep orange coloured gas. It is capable of 
combining with much iodine, when they are heated to- 
gether ; its colour becomes in consequence deeper, and 
the chloriodic acid and the iodine rise together in the 
elastic state, 

21. A triple compound of this acid and sodium may 
exist, according to Sir H. Davy, in sea water, and in 
common soot. 

22. Chloro-prussic ackl, or chloro-cyanic acid, was 
formerly called oxy-prussic acid ; it is found, however, 
not to contain oxygen, but is a compound of chlorine 
and prussic acid. 

23. When hydro-cyanic acid is mixed with chlorine, 
it acquires new properties. Its odour is much increas- 



190 INTRODUCTION 

ed. It no longer forms Prussian blue with solutions of 
iron, but a green precipitate, which becomes blue by 
the addition of sulphurous acid. 

24. It consists, according to M. Gay Lussac, of equal 
volumes of chlorine and prussine r or the base of the 
prussic acid. 

25. Fluoboric acid is obtained frcm<fiuor spar and vi- 
treous boracic acid, by mixing together one part boracic 
acid, two fluor spar, and twelve oil of vitriol, and distil 
ling in a glass retort. It is obtained in the form of gas- 

26. 100 cubic inches of this gas weigh ^ 8.5 grains, 
lis density is to that of air as 2.371 to 1.000. It is col- 
oorlesSy its smell is pungent, resembling that of muriatic 
acid. It will not support respiration or combustion. It 
reddens strongly the tincture of turnsole. It attacks vio- 
lently animal and vegetable substances. Exposed to a 
high temperature, it is not decomposed. It is condensed 
by cold without changing its form. When it is put in 
contact with oxygen or air, it suffers no change, except 
seizing, at ordinary temperatures, the water which they 
contain, and becomes a liquid, emitting extremely dense 
fumes. It operates in the same way with all the gases, 
which contain moisture. However little tbey may con- 
tain, it occasions in them very perceptible vapours.. 

27. Fluoboric acid gas is very soluble in water. It 
can combine, according to Dr. Davy, with 700 times its 
own volume, or twice its weight at the ordinary tem- 
perature and pressure of the atmosphere. The liquid 
has- a specific gravity of 1.770. 

28. Fluo-silicic acid is a combination of fluorine with 
silicon. It contains in 100 parts 61.4 silicon. 

Exp. If the mixture of fluor spar and sulphuric acid 
be distilled in glass vessels, the glass would be acted up- 



TO CHEMISTRY. J9| 

on, and a peculiar gaseous substance be produced, which 
must be collected over mercury. 

29. This gas is very heavy, 100 cubic inches of it 
weighs 110.77 grains ; its specific gravity is to that of 
air as 3.632 to 1.000. It is about 48 times denser than 
hydrogen. When brought into contact with water, ft 
instantly deposites a gelatinous substance,which is hydrate 
of silica. It produces white fumes when suffered to pass 
into the atmosphere. It is not affected by any of the 
common combustible bodies ; but when potassium is 
strongly heated in it, it takes fire and burns with a deep 
red light, the gas is absorbed, and a rose coloured -sub- 
stance is formed, which yields alkali to water, with slight 
effervescence, and contains a combustible body. 

PRACTICAL QUESTIONS. 

How is fluoric acid obtained ? 

Who ascertained the real nature of fluor spar ? 

How may fluoric acid be prepared ? 

What are its properties ? 

What is fluoric acid considered to be ? 

What does hydriodic acid resemble ? 

How may it be prepared ? 

What are its characteristics ? 

How is it decomposed ? 

How is ferroprussic acid obtained ? 

What are its characteristics ? 

What enables it to displace acetic acid ? 

What is its composition ? 

What is hydrosulphurous acid ? 

W T hat is hydrotellurous acid ? 

What is sulphuroprussic acid ? 

With what does it combine ? 

What is chloriodrc acid ? 



102 INTRODUCTION 

What are its characteristics ? 

Where may a triple compound of this acid and sodium 
exist? 

What is chloroprussic acid ? 

What is the effect when hydrocyanic acid is mixed 
with chlorine ? 

Of what does it consist ? 

From what is fluoboric acid obtained ? 

What are its characteristics ? 

Is it soluble in water ? 

What is fluosilicic acid ? 

What is its weight and properties ? 



CHAP. XX. 

Acids of organic origin* 

1. Acids of organic origin are those obtained from 
animal and vegetable substances. Those which have 
hitherto been discovered, amount to thirty-eight. 

2. Aceric acid is a peculiar acid, said to exist in the 
juice of the maple, (acer saccharinum.) It is decompos- 
ed by heat, like the other vegetable acids. 

3. Acetic acid is the same acid, which, in a diluted 
state, is called vinegar, and formerly acetous acid. 

4. This acid is found combined with potash in the 
juice of many plants. It is the result, likewise, of spon- 
taneous fermentation, to which liquid, vegetable and ani- 
mal matters are liable. 

b. The varieties of acetic acid known in commerce, 
are four. 1. Wine vinegar. 2. Malt vinegar, or that 
obtained from beer. 3 Sugar vinegar, or the result of 



TO CHEMISTRY. 193 

the acetic fermentation of saccharine solutions. 4. Wood 
vinegar or pyroligneous acid. 

6. Acetic acid enters into combination with the salifi- 
able bases, and forms substances called acetates, 

7. They are characterized by the pungent smell of 
vinegar which they exhale on mixing them with sulphur- 
ic acid. Tffey are all soluble in water ; many of them 
cannot be crystallized. About 30 different acetates have 
been formed. 

8. Acetic acid when highly concentrated is, pungent 
and acrid, and corrodes animal -substances. 

9. Amniotic acid is obtained from the liquor ^amnii cff 
the cow, by evaporation and crystallization. 

10. These crystals when washed in cold water, are 
white and shining, slightly acid to the taste, redden lit- 
mus paper, and are a little more soluble in hot than cold 
water. They are likewise soluble m alcohol. This 
acid forms w T ith the alkalies, very soluble salts. When 
thrown on burning coals the crystals of the acid swell? 
turn black, give out ammonia and prussic acid, and 
leave* a bulky coaL 

11. Benzoic acid was so named because it was first 
obtained from the resin of benzoin. It is found in a va- 
riety of substances. If we concentrate the urine of hors- 
es and cows, and pour muriatic acid on the mass, a copi. 
eus precipitate of benzoic acid will be formed. It is us- 
ed in medicine under the name of flowers of Benja- 
min. 

12. Benzoic acid is a very fine, light substance, in 
needle-form crystals. It combines with alkalies, earths 
and metallic oxides, forming benzoates. It is soluble in 
boi-ting water, and also in alcohol, in the latter case it is- 

4>recipitated by the addition of water. 

1 3. Bole tic acid is extracted from the expressed juice 

17 



191 INTRODUCTION 

*f the boletus pseudo-igniariusj a species of mushroom. 

14. Boletic acid, when properly prepared, consists of 
crystals of irregular four sided prisms, of a white colour, 
permanent in the air. Its taste resembles cream of tar- 
tar. At the temperature of 63° it dissolves in 180 
fime3 its weight of water, and in 45 of alcohol. It red- 
dens vegetable blues. It precipitates the red oxide of iron, 
and the oxides of silver from their solutions in nitric acid. 
It sublimes, when heated, in white vapours, and is con. 
densed into a white powder. 

15. Camphoric acid is obtained from camphor, by 
distilling ijt with nitric acid, it is in the shape of crys- 
tals. 

16. These are in the form of parallelopipedons, but 
of so delicate a structure, that they effl ore cse in the air. 
They are of a slightly acid taste, and redden vegetable 
blues. The acid forms camphorates with alkalies, earths 
and metallic oxides, 

17. Caseic acid is the name given to the acid found 
in cheese to which the flavour has been ascribed. 

18. The citric acid is obtained from the juice of lem- 
ons and limes ; it is also found in several other fruits. 

19. It crystallizes in beautiful prisms, is extremely 
acid and very soluble in water. It combines with the 
earths and metallic oxides, forming salts called citrates. 

20. It is much used in calico printing, and in medi- 
cine. 

21. Formic acid is obtained from ants, either by dis- 
tillation or infusion in boiling water. 

22. It has a very sour taste, and continues liquid at a 
low temperature. Its specific gravity is 1.1158 at 68°. 
It has been used by quacks as a remedy for the tooth- 
ache. 

23. Fungic acid is obtained from several species of 
mushrooms. 



TO CHEMISTRY. 195 

24. It is a colourless,unciwstallizable and deliquescent 
mass, of a very sour taste. It precipitates from a solution 
of acetate of lead,a flocculant mass which is soluble in dis- 
tilled vinegar. It unites with alkalies and earths, and 
forms salts called /ungates. 

25. Gallic acid is obtained from nutgalls, and from the 
bark of other trees in which the astringent principle re- 
sides. 

23. Its most distinguishing characteristic is its great 
affinity for metallic oxides, so, as when combined with 
tannin, to take them from powerful acids. The more 
readily the metals part with their oxygen, the easier 
they are alterable by gallic acid. 

Exp. To a solution of Gold, gallic acid imparts a 
green hue, and a brown precipitate is formed, which 
readily passes to the metallic state,, and covers the solu- 
tion with a shining golden pellicle. A similar effect is 
produced with a solution of nitrate of silver. Mercury 
is precipitated of an orange colour, copper brown ; bis- 
muth of a brown colour ; lead, white ; iron, black. 

27. The gallic acid is of extensive use in dying, as it 
constitutes one of the principal ingredients in all the 
shades of black, and is employed to fix or improve sev- 
eral other colours. It is a well known ingredient in 
ink. 

28. Kinic acid is a peculiar acid ottrlned from cin- 
chona, or Jesuit's bark ; when concentrated it yields reg- 
ular crystals. 

29. It is decomposed by heat, while it forms a solu- 
ble salt with lime, it does not precipitate silver or lead 
from their solutions. 

30. Laccic acid is obtained from a substance called 
Stick Lac. 

31. It crystallizes, has a wine yellow colour, has an 



T96 i^TRODUcntpr 

acid taste, and is soluble in water, alcohol and etHer. 
It precipitates lead and mercury white ; but it does not 
affect lime, barytes or silver in their solutions. It throws 
down the salts of iron white. With lime, soda, ancF 
potash, it forms deliquescent salts soluble in alcohol. 

32. Lactic acid is obtained from ssur whey or 
milk. 

33. When pure, it has a brown yellow colour and ** 
sharp sour taste, which is much weakened by diluting it 
with water. It is without smell in the cold, but emits 
when heated, a sharp sour odour. It cannot be made to 
crystallize, and does not exhibit the slightest appearance 
of a saline substance, but dries into a thick and smooth 
varnish, which slowly attracts moisture from the air. It 
is very easily soluble in alcohol. With earths, alkalies 
and metallic oxides it affords peculiar salts, and those are 
distinguished by being soluble in alcohol, and drying into 
a mass like gum,, which slowly becomes moist in the at- 
mosphere, 

34. Rampie acid is formed from the slow combustion 
of ether. 

35. Lampic acid, when first procured, is a colourless 
fluid of an intensely sour taste and pungent smell. Its va- 
pour, when heated, is extremely irritating and disagree- 
able. Its specific gravity varies according to the care 
with which it has been procured, from less than 1.000 to 
1.008. It unites with alkalies, earths and metallic oxides^ 
forming compounds called lampates. 

3G. Lithic acid was discovered about the year 1776, 
by Mr. Scheele. in analyzing the human calculi, in many 
of which it constitutes a greater part, and in some it forms 
almost the whole. It is often called uric acid. 

37. Its colour is yellow, and it has a cool, bitter taste. 
It dissolves readily in water and in alkaline solutions. 



TO CHEMISTRY, 197 

from which it is norprecipitated by acids. It is sparing- 
ly soluble in alcohol. It combines with alkalies and 
earths, forming salts called lithates. 

38. Malic acid, is that taken from apples, and appears 
to be the same as the sorbic acid. 

39. Meconic acid is a constituent of opium, and is pre- 
pared from that drug. 

40. It has a strong sour taste, which leaves behind it 
an impression of bitterness. It dissolves readily in water 
alcohol and ether. Reddens vegetable blues, and chan- 
ges the solution of iron to a cherry red colour. It unites 
with the alkalies and forms compounds called maconiates. 

Menispermic acid is obtained from the seed of the mc- 
nispermum cocculus*. 

42. It occasions no precipitate with lime water, with 
nitrate of barytes it yields a grey precipitate ; with ni- 
trate of silver it yields a deep yellow; and with sulphate 
of magnesia a copious precipitate. 

43. Margaric acid is an acid obtained from. soap 
made of pork grease, and potash. It is procured in the 
form of pearly white crystals. 

44. It has no taste. Its smell is feeble,^ little resem* 
bling that of melted wax. Its specific gravity is inferior 
to water. It melts at 134° F. into a very limpid colourless 
liquid, which crystallizes on cooling, into brilliant crys- 
tals of the purest white. It is insoluble in water, but 
very soluble in alcohol. Specific gravity 0.800. Cold 
margaric acid has no action on litmus when cold, but when 
heated so as to soften without melting, the blue is redden- 
ed. It combines with the salifiable bases and forms neu- 
tral compounds called ma rgarates. 

45. . Melascic acid is that which at present is procur 
ed from Molasses, which is thought to be a peculiar acid' 
by some* 

17* 



198 INTRODUCTION 

43. Mellitic acid is obtained from the Mellite, or hon- 
ey stone, and is thought to be of vegetable origin. 

47. It crystallizes in fine needles,or small prisms. Its 
taste is at first of a sweetish sour, which is. followed by a 
bitterness. On a plate of hot metal it is readily decom- 
posed and dissipated in copious grey fumes, leaving be- 
hind a small quantity of ashes, that do not change either 
red or blue litmus. It unites with some of the alkalies 
and forms mellitates. 

48. Moroxylic acid was obtained from a white sub- 
stance found on the bark of the white mulberry, growing 
in the botanic garden of Palermo. It is considered as re- 
sembling nearly the succinic acid, but its characters have 
not been fully examined* 

49. Mucic acid was formerly called saccholactitf acic 1 : 
because it was obtained from sugar of milk ; but as all the 
gums appear to afford it, and the principal acid in the 
sugar of milk is oxalic, it is, in general, distinguished by 
the name of mucic acid. 

50. It is obtained from gum in the form of a pulverulent 
mass. It is soluble in about 60 parts of hot water, and 
by cooling, a fourth part separates in the form of scales 
thatgrow white in the air. It decomposes the muriate 
of barytes and both the nitrate and muriate of lime. It 
Arms with the metallic oxides, salts scarcely soluble. It 
precipitates the nitrates of silver, lead and mercury. 
It consists, according to Berzelius, 

cf Hydrogen, 5.115 
Carbon, 33.430 
Oxygen, 61.465 



100.000 
5k Oleic^acid is obtained from Jiog-s lard. 
52. It is an>ily fluid without taste or smell. Its sj>€- 



TO CHEMISTRY. 199 

ciiic gravity is 0.914. It is generally soluble in its own 
weight of boiling alcohol, of the specific gravity 0.7952. 
100 of the oleic acid saturates 16.58 of potash ; 10.11 of 
soda, 7.52 of magnesia, 14.83 of zinc, and 13.93 of pro- 
toxide of copper. 

53. Oxalic acid is the acid which abounds in wood 
sorrel, and which, combined with a small portion of pot- 
ash which exists in that plant, has been sold under the 
name of salt of lemons. It is obtained in quantities from 
sugar. 

54. This acid exists in the form of crystals ; they have 
a strong acid taste, and act powerfully on vegetable col- 
ours. The acidity is so great, that when dissolved in 
3600 times their weight of water, it reddens litmus pa- 
per. These crystals dissolve in twice their weight of 
water. They effloresce in the air. It combines with 
earths, alkalies and metallic oxides, and forms salts, 
known by the name of oxalates. It is capable of oxidiz- 
ing lead, copper, iron, &c. It has a great affinity for 
iron ; on this principle it is employed for removing ink 
spots from linen. It is used as a test to detect the exis- 
tence of lime in solution. 

• Exp. Drop a little of the acid into water supposed to 
contain lime ; if there be any, a white powder is imme- 
diately precipitated. 

55. Purpuric acid is found in some of the urinary 
calculi. 

56. It usually exists in the form of a very fine pow- 
der, of a slightly yellowish, or cream colour. It pos- 
sesses no smell or taste. Its specific gravity is greater 
than that of water. It is scarcely soluble in water. One 
tenth of a grain boiled in 1000 grains of water, was not 
entirely dissolved* The water, however, assumed a 



200 INTRODUCTION 

purple tint. It is insoluble in alcohol or ether. It 
unites with the alkalies, and forms purpurates, 

57. Pyrolithic acid is obtained from uric acid concre- 
tions, by distillation. 

50. It is obtained in the shape of acicular crystals. — 
They are soluble in four parts of cold water, and the so- 
lution reddens vegetables blues. Boiling alcohol dis- 
solves the acid, but on cooling, it deposits it in fine white 
grains. Nitric acid dissolves it without changing it. At 
a red heat it is decomposed. 100 parts consist of 

Oxygen 44.32 

Carbon 28.29 

Azote 16.84 

Hydrogen 10. 



99.45 

59. Pyromalic acid is obtained from malic or sorbic 
acid, by distillation ; when pure, it is in the form of 
crystals. 

60. These crystals are permanent in the air, they 
melt at 118° F. and on cooling, they form a pearl colour* ■ 
ed mass of diverging needles, when thrown on coals 
they evaporate^and the smoke produces cough. Expos- 
ed to a low heat in a retort, they are partly sublimed in 
needles and are partly decomposed. They are very so- 
luble in strong alcohol and in double their weight of wa- 
ter at ordinary temperatures. The solution reddens 
vegetable blues, and forms with alkalies neutral salts, 
called pyromalates. 

61. Pyrotartaric acid is obtained from tartar, by dis- 
tillation. The word pyro^ signifying when prefixed to 
the name of an acid, that it is prepared by heat. 

62. It has a very sour taste> and reddens powerfully 
the tincture of turnsole. Heated in an open vessel, the 



TO CHEMISTRY. 20 1 

acid rises in a white smoke. It is very soluble in water, 
from which it is separated in crystals by evaporation. It 
combines with the salifiable bases, forming pyroiartraies. 

63. Rosacic acid, an acid obtained from the sediment 
found in the urine of persons, labouring under intermit-* 
tent fevers. This sediment is of a rose colour, occa- 
sionally in reddish crystals. 

64. This acid is solid, of a lively cinnabar colour, 
without smell, with a faint taste, but reddening litmus 
very sensibly. On burning coals, it is decomposed into 
a pungent vapour. It is very soluble in water, and even: 
attracts humidity from the atmosphere. It is soluble in 
alcohol, and combines with the salifiable bases. 

65. Sebacic acid is obtained from hog's lard ; it is in 
the form of crystals of small white needles. 

66. It is inodorous, of a slight taste, but it percepti- 
bly reddens litmus paper. Its specific gravity is greater 
than that of water. Exposed to heat, it w decomposed,' 
melts like fat, and is partially evaporated. The air has 
no effect upon it. Alcohol dissolves it abundantly at 
ordinary temperatures. It unites with the alkalies, and 
forms salts. 

67. Sorbic acid is obtained from the berries of the 
mountain ash, sorbus, or pyrus aucuparm. It appears that 
sorbic and pure malic acids are the same. 

68. It unites with the alkalies, and forms salts called 
sorbaies, 

69. Suberic acid is obtained from cork, by means of 
nitric acid. 

70. When pure, it is -white -and pulverulent, having a 
feeble taste and little action on litmus. It is soluble in 
80 parts of water at 55£°, and in 38 parts at 140°; It is 
more soluble in alcohol, from which water throws down 



20^ INTRODUCTION 

a portion of the suberic acid. It unites with the alka- 
line bases, and forms suberates. 

71. Succinic acid is obtained from amber by sublima- 
tion. It is, when pure, in white transparent crystals of 
a prismatic form. Their taste is somewhat sharp, and 
they redden powerfully tincture of turnsole. Heat melts 
and partially decomposes succinic acid. Air has no ef- 
fect upon it. It is soluble in both water and alcohol. It 
forms salts with the earths and alkalies, called succinates. 

72. Sulphovinic acid is a name given to a clas3 of 
acids, which may be obtained by digesting alcohol and 
sulphuric acid together, with heat. It seems probable, 
that this acid is the hyposulphuric combined with a pe- 
culiar oily matter. 

73. Tartaric acid is an acid obtained from tartar, 
which is a hard substance, adhering to the casks in which 
wine is kept. It may be procured in needle or laminat- 
ed crystals, by evaporation. 

74. Its taste is extremely sour and agreeable ; it is 
often used in making punch, instead of lemon juice. It 
is very soluble in water. Burnt in an open fire, it leaves 
a coaly residuum ; in close vessels, it gives out carbonic 
acid, and carburetted hydrogen gas. By distilling nitric 
acid off the crystals, they may be converted into oxalic 
acid, and the nitric acid passes to the state of nitrous. — 
It unites with the salifiable bases and forms tartrates. 

75. Zumic acid is obtained from sour rice, putrefied 
juice of beet roots, from the sour decoction of carrots, 
peas, &c. 

76. It is without colour, does not crystallize, has a 
very acid taste. It forms with alumina a substance re- 
sembling gum, and with magnesia, one unalterable in 
the air, in little granular crystals, soluble in 25 parts of 



TO CHEMISTilY. 2CJ, 

rater at 66° F. It forms salts, possessing* peculiar cha- 
racteristics, with the other salifiable bases. 

PRACTICAL QUESTIONS; 
What are acids of organic origin ? 
What is acetic acid ? 
Where is it found ? 

What are the varieties of acetic acid ? 
What are acetates ? 
How are they characterized ? 
How is acetic acid when highly concentrated 1 
From what is amniotic acid obtained ? 
What are its characteristics ? 
What is Benzoic acid ? 
What are its characteristics ? 
Trom what is boletic acid obtained ? 
What are its characteristics ? 
What is camphoric acid? 
What are its characteristics ? 
What is caseic acid ? 
What is the citric acid ? 
What are its characteristics ? 
?s it much used ? 

From what is formic acid obtained '? 
What are its properties ? 
From what is fungic acid obtained ? 
What are its characteristics ? 
From what is gallic acid obtained ? 
What are its characteristics ? 
Is it much used ? 
What is kinic acid ? 
What are its properties ? 
From what is laccic acid obtained ? 
What are its^ properties ? 



£04 INTRODUCTION 

From what is lactic acid obtained ? 

What are its properties ? 

What is lampic acid ? 

What are its properties ? 

What is lithic acid ? 

What are its characteristics ? 

What is malic acid ? 

What is meconic acid ? 

What are its characteristics 3 

What is menispermic acid ? 

What are its properties ? 

What is margaric acid ? 

What are its properties ? 

What is melassic acid ? 

From what is mellitic acid obtained '? 

What are its properties ? 

From what is moroxylic acid obtained ? 

What is mucic acid ? 

What are its properties ? 

What is oleic acid ? 

What are its properties'? 

What is oxalic acid ? 

What are its characteristics? 

What is purpuric acid ? 

What are its characteristics ? 

From what is pyrolithic acid obtaitied? 

What are its characteristics ? 

How is pyromalic acid obtained ? 

What are its properties ? 

From what is pyrotartaric acid obtained I 

What are its characteristics ? 

What is rosacic acid ? 

What are its characteristics ? 

From what is sebacic acid obtained ? 



TO CHEMIStRYo 205 



What are its characteristics ? 

What is sorbic acid ? 

From what is suberic acid obtained ? 

What are its characteristics ? 

What is succinic acid ? 

What is sulphovinic acid ? 

What is tartaric acid? 

W r hat are its characteristics ? 

From what is zumic acid obtained ? 

What are its characteristics ? 



CHAP. XXL 

Of Chlorine, 

1. The term chlorine, which signifies a yellowish 
green colour, is applied to a substance, which was for- 
merly called oxymuriatic acid gas ; it is obtained by mix- 
ing muriatic acid with oxide of manganese. 

2. The merit of this discovery is justly due to Sir H. 
Davy, who, after submitting the gas to a variety of ex- 
periments, pronounced it to be an elementary sub- 
stance. 

3. Sir H. Davy submitted to the action of muriatic 
acid gas, potassium ; by which, more than one third of 
its volume of hydrogen was produced. He states that 
muriatic acid can in no instance be procured from oxy- 
muriatic acid, unless water be present ; or from dry mu- 
riates, unless water or its elements be present. 

According to the experiments of M. M. Gay Lussac 
and Thenard, muriatic acid gas contains one quarter of 
18 



ZQS INTRODUCTION 

its weight of water, and oxymuriatic acid is not de- 
composable by any substance but hydrogen, or such as 
can form triple combinations with it. 

4. One of the most singular facts is, that charcoal, 
even when ignited to whiteness in oxymuriatic or muri- 
atic acid gases, hy the voltaic battery, effects no change 
in them, if it has been previously freed from hydrogen 
and moisture, by intense ignition in vacuo. 

Observation. The above experiment lead Sir H. Da- 
vy to doubt the existence of oxygen in oxymuriatic gas, 
which has been supposed to contain it above all others, 
in a loose and active state. He then proceeded to a very 
rigorous investigation of nature, which terminated in an 
entire conviction that oxymuriatic acid gas was a simple 
substance, which he placed in the same rank with oxy- 
gen, and removed it from the class of acids. This opin- 
ion is now pretty generally embraced by all the most 
celebrated' chemists, although most of the phenomena 
attending the action of this substance, may be accounted 
for on the supposition that chlorine be a compound bod}\ 

Exp. 1. If oxymuriatic acid gas be introduced into a 
receiver exhausted of air, containing a little tin, and the 
metal be gently heated, the tin and the gas disappear, 
and a limpid fluid, called the liquor of Libavius, is form- 
ed. If this substance be a combination of muriatic acid 
and oxide of tin, the oxide w*ll be separated from it, by 
means of ammoniacal gas. 

Exp. 2. Admit ammoniacal gas over mercury to a 
small quantity of the liquor of Libavius, it will be ab- 
sorbed, and much heat will be extricated, and no gas 
generated ; a solid result is obtained, which is of a dull 
white colour, when heated, the whole is volatilized, pro- 
ducing dense pungent fumes. 



TO CHEM15THV. 207 

& When oxymuriatic acid and ammonia are made to 
act upon each other, water is not formed. This un- 
doubtedly would be the result, if the oxymuriatic acid 
was a compound body, as the two substances would con- 
tain the elements of that fluid. 

6. When chlorine is acted upon by nearly an equal 
volume of hydrogen, a combination takes place between 
them -and muriatic acid gas is the result. 

7. When oxymuriatic acid gas is acted on by mercu- 
ry, or any other metal, oxymuriatic acid, or chlorine is 
attracted from the hydrogen by the stronger affinity of 
the metal, and an oxymuriate is produced. 

6. As oxymuriatic acid is not known to contain oxy 
gen, its name appears absurd, and ought to be erased 
from the chemical nomenclature, and that of chlorine or 
some other appropriate term substituted. 

9. Chlorine combines with inflammable bodies to 
form simple binary compounds ; and in those cases, when 
it acts upon oxides, it either expels their oxygen, or 
causes it to act upon new combinations. 

10. The oxygen does not arise from the decomposi- 
tion of the oxymuriatic acid, but from the oxide, as is 
evident from its being exactly equal to the quantity con- 
tained in the oxide used. 

11. It appears pretty evident that there is no acid 
property in oxymuriatic acid, combined with oxygen, be- 
cause if it were so, it ought to be exhibited in the fluid 
compound of one proportion of phosphorus, and two of 
oxymuriatic gas ; on the old hypothesis, it would consist 
of muriatic acid, and phosphorous acid ; but this substance 
has no effect on litmus paper, and does not act under 
common circumstances, as fixed alkaline bases, such as dry 
Jime, or magnesia* 



208 INTRODUCTION 

12. Oxymuriatic acid, like oxygen, must be combin- 
ed in large quantities, with peculiar inflammable matter, 
to form acid matter. 

Illustration. In its union with hydrogen, it instantly 
reddens the driest litmus paper, though a gaseous body ; 
contrary to acids, it expels oxygen from protoxides and 
combines with peroxides. 

13. When potassium is burnt in chlorine, a dry com- 
pound" is obtained. 

14. The bleaching properties of chlorine was ac- 
counted for on the old theory, by supposing that it de- 
stroyed colours by parting with its oxygen, but by the 
new, the oxygen is derived from the water, with which 
it must always be combined, in order to produce the ef- 
fect, by a double affinity, that of hydrogen for chlorine, 
and of the colouring matter for oxygen. 

1 5. Chlorine is not capable of being condensed at a 
low temperature, nor crystallized. 

16. The solution of chlorine in water, freezes more 
readily than pure water ; but the pure gas dried with 
muriate of lime experiences no change whatever, at a 
temperature of — 40° F. 

17. Chlorine is of a greenish yellow colour. Its 
odour and taste are disagreeable, which is one of its dis- 
tinguishing characteristics, as it is impossible to mistake 
it for any other gas. When breathed, even when much 
diluted with air, it occasions a sense of strangulation, 
constriction of the thorax, and a copious discharge from 
the nostrils. If respired in larger quantities, it excites 
violent coughing and spitting of blood, and if continued, 
would speedily destroy the individual, in violent distress. 
Its specific gravity is 2.4733. In its perfectly dry state, 
it has no effect on dry vegetable colours ; with the aid 



TO CHEMISTRY. 209 

of a little moisture, it bleaches them into a yellowish 
white] 

Exp. 1. If a lighted wax taper be immersed in this 
gas, it consumes very fast, with a dull reddish flame and 
much smoke. 

Note. — The taper will not burn at the surface of the 
gas. 

Exp. 2. Immerse a small quantity of sulphuret of 
antimony, powdered into a jar containing chlorine, it 
will immediately take fire and burn spontaneously, the 
result will be chloride of antimony. The same effect 
will take place with copper, tin, arseniG and zinc, in 
powder. 

Exp. 3. If phosphorus be immersed, as' above, it 
will take fire at ordinary temperatures, and chloride of 
phosphorus will be formed. 

18. Chlorine combines with alkalies, and forms salts, 
possessed of various properties ; that with potash is most 
generally known. It was formerly called hyper+oxymuriate 
of potash, now chlorate* 

Exp. 1. Put two grains of chlorate of potash in pow- 
der into a mortar, and add one grain of sulphur. Mix 
them very accurately by gentle triture, and then having 
collected the mixture to one part of the mortar, press 
the pestle upon it suddenly and forcibly, a loud detona- 
tion will ensue. . 

Exp. 2. If the mixed ingredients be wrapped in some 
strong paper, and then struck with a hammer, a still 
louder report will be produced. 

Exp. 3. If five grains of this salt be mixed with half 
the quantity of powdered charcoal, in a similar manner, 
and the mixture be strongly triturated, it will inflame, 
but with little noise, 
18* 



210 INTRODUCTION 

Exp. 4. Mix a small quantity of sugar with half its 
weight of the salt, dip a glass rod into sulphuric acid, 
and let a drop fall on the mixture, an instantaneous in- 
flammation will take place. 

Exp. 5 Lay two trains, one of gunpowder, and the 
other of chlorate of potash, in such a manner, as that 
they may touch at one end, and diverge at the other, in 
the form of an acute angle ; then apply an ignited coal 
at the point of contact ; both will be inflamed at the same 
time, but the gunpowder will burn comparatively slow. 

19. Chlorine is capable of combining with two pro- 
portions of oxygen, which are very interesting in their 
properties, called the protoxide and deutoxide of chlorine, 
or chlorous and chloric oxides. 

Exp. Put chlorate of potash into a small retort, and 
pour in twice as much muriatic acid as will cover it, di- 
luted with an equal volume of water, by the application 
of a gentle heat, the gas is evolved ; it must be collected 
over mercury. 

20. Its tint is much more lively, and more yellow 
than chlorine ; from this circumstance, Sir H. Davy cal 
led it Euchlorine. Its smell is peculiar, and approaches 
to that of burnt sugar. It is notrespirable. It is soluble 
in water, to which it gives a lemon colour. Water ab- 
sorbs 8 or 10 times its volume of this gas. Its specific 
gravity is to that of common air, nearly as 2.40 to 1. 

21. This gas must be collected and examined with 
great care, and in very small quantities. A gentle heat? 
even that of the hand, will cause its explosion, with such 
force as to burst thin glass. In the act of explosion, the 
elements arc separated with great violence and some light. 

22. The metals which act upon chlorine, will not act 
upon this at common temperatures ; but when the oxy- 
gen is separated, they inflame in the chlorine. 



TO CHEMISTRY. 211 

Exp. Let a little gold leaf be introduced into a bottle 
filled with the protoxide of chlorine, it will undergo no 
change ; but if a heated glass tube be applied to the gas, 
in the neck of the bottle, a decomposition takes place, 
and the oxygen and chlorine will be detached from each 
other, and at the same moment, the leaf will inflame and 
burn with great brilliancy. 

23. The deutoxide of chlorine or chloric oxide is 
formed by mixing Mty or sixty grains of chlorate of pot- 
ash with a small quantity of sulphuric acid in a wine 
glass, very little effervescence takes place, but the acid 
gradually acquires an orange colour, and a dense yellow 
vapour, of an agreeable smell, floats on the surface. If 
this be put into a retort, and heated, by means of hot wa- 
ter, a gas is obtained, which may be received over mer- 
cury. 

24. Water absorbs more of it than of the protoxide. 
Its taste is astringent. It destroys vegetable blues with- 
out reddening them. When phosphorus is introduced 
into it, an explosion takes place. When heat is applied, 
the gas explodes with more violence, and produces more 
light than the protoxide. When thus exploded, two 
measures of it are converted into nearly three measures, 
which consist of a mixture of one measure chlorine, and 
two measures oxygen. Hence it is composed of 1 atom 
chlorine, and 4 atoms oxygen. 

25. When chlorine is passed through a solution of ni- 
trate of ammonia, the gas is rapidly absorbed, and a film 
appears on the surface, which soon collects into yellow- 
ish drops, that sink to the bottom of the liquor. 

26. This is the most powerful detonating compound 
known. When gently warmed, it explodes with such 
violence, as to be attended with very great danger. It 
explodes in certain circumstances, with or without heat, 



212 INTRODUCTION 

Exp. If a globule of the fluid be thrown into olive 
oil, turpentine, or nr^-htha, it explodes without heat, 
and so violently as to shatter the glass vessel in which it 
takes place. 

PRACTICAL QUESTIONS. 

To what is the term chlorine applied ? 

To whom is the merit of the discovery due ? 

What method did Sir H. Davy take to prove that this 
was an elementary substance ? 

What effect does charcoal produce on chlorine ? 

What did Sir H. Davy infer from these ? 

What other experiments can you adduce, illustrative 
of the hypothesis ? 

Is water formed by the action of oxymuriatic acid and 
ammonia ? 

W T hat is formed by the action of chlorine and hydro- 
gen*? 

What is the effect of the action of mercury on oxymu- 
riatic acid? 

What phenomenon is produced,when oxymuriatic acid 
acts on inflammable bodies ? 

Whence does the oxygen arise in this case? 

How does it appear that there is no acid property 
combined with oxygen in oxymuriatic acid gas ? 

What is necessary in order that oxymuriatic acid gas 
may form acid matter ? 

In its union with hydrogen, what is its effect ? 

What is obtained from the combustion of potassium in 
chlorine ? 

How do you account for the bleaching properties of 
chlorine ? 

Can chlorine be condensed ? 

What are the characteristics of chlorine ? 



10 CHEMISTRY. 21 3 

What is the combination of chlorine with alkalies ? 
Illustrate the properties of chlorate of potash by ex- 
periments ? 

What are the combinations of chlorine with oyxgen ? 
W T hat are the properties of protoxide of chlorine ? 
Does this substance easily explode 2. 
"Will metals act upon this gas ? 
How is the deutoxide of chlorine formed t 
What are its properties ? 
Does chlorine unite with nitrogen ? 
What are the characteristics of the compound ? 



CHAP. XXII. 

Of Iodine. 

1; Iodine is a name given to an elementary substance. 
It wa3 accidentally discovered by M. De Courtois, a man- 
ufacturer of salt-petre, at Paris, in 1812. In his process 
of procuring soda from the ashes of sea weed, he found 
the metallic vessels much corroded ; and in examining 
into the cause he made this important discovery. It de- 
rived its first illustration from M. M. Clement, and De- 
sormes, who named it iodine from the Greek word signi- 
fying like a violet, from the violet coloured vapour which 
it formed. 

2. Iodine has been found in the following sea weeds, 
Fucus cartilagineus ; F. membranaceus ; F. filamentosus ; 
F. rub em ; F nodosus ; F. serratus ; F, siliquosus ; F 
palmatus ; F. Jikun ; F. digitatus ; F< saccharimus ; Uha 
umbilicalis ; U. pavonia ; U lima ; and in sponge. 

3 It is from the ashes of sea weed, or kelp, that to- 



214 INTRODUCTION 

dine, in quantities, is to be obtained The following 
method of extracting it, is given by Br. Wollaston. Dis~ 
solve the soluble part of kelp in water. Concentrate the 
liquid by evaporation, and separate all the crystals that 
can be obtained. Pour the remaining liquid into a clean 
vessel and mix with it an excess of sulphuric acid. Boil 
this liquid for some time. Sulphur is precipitated, and 
muriatic acid driven off. Decant the clear liquid and 
strain it through wool. Put it into a small flask, and mix 
with it as much black oxide of manganese, as sulphuric 
acid. Apply at the top a glass tube shut at one end. 
Then heat the mixture in the flask. The iodine sublimes 
into the glass tube. 

4. Iodine, when properly prepared, is a solid of a 
greyish black colour and metallic lustre. It is often in 
the form of scales, sometimes in rhomboidal plates very 
large and very brilliant. Its fracture is lamellated, and 
it is soft and friable to the touch. Its taste is very acrid, 
though it be very sparingly soluble in water. It is a dead 
ly poison. It gives a deep brown stain to the skin, which 
soon vanishes by evaporation. In odour and power of 
destroying vegetable colours, it resembles very dilute 
aqueous chlorine. Its specific gravity at 62 1-2° is 4.948. 
It dissolves in 7Q00 parts of water. The solution is of an 
orange yellow colour, and in small quantities tinges starch 
of a purple hue, which is the most delicate test. When 
this substance is put into a liquid containing the iodine t 
in a state of liberty, it detects the presence of so small a 
quantity as the 4 joio o tn D y tfte klue colour which it 
forms. 

It evaporates quickly at ordinary temperatures. Boil- 
ing water aids its sublimation. The specific gravity of 
its violet vapour, is 8.678. It is a non-conductor of elec- 
tricity. 



tO CHEMISTRY 215 

5. Iodine is incombustible, but with azote it forms a 
curious detonating compound ; and in combining with sev- 
eral bodies the intensity of mutual action is such as to pro- 
duce the phenomena of combustion. 

6. When iodine and oxides act upon each other in 
contact with water ; the water is decomposed, its hydro- 
gen unites with iodine to form hydriodic acid, while its 
oxygen produces with iodine, iodic acid. All the oxides 
however, do not produce the same results ; only such as 
potash, soda, barytes, strontian, lime and magnesia. The 
oxide of zinc, precipitated by ammonia, from its solution 
in sulphuric acid, and when well washed, gives no trace 
of iodate or hydriodate. 

7. Iodine dissolves in carburet of sulphur, producing 
in very minute quantities, a fine amethystine tint to the 
liquid, 

8. If iodine and hydrogen be heated in dry hydrogen 
gas, an expansion of its volume takes place, an acid gas 
is formed which is very absorbable by water ; and acts so 
powerfully on mercury that it cannot be preserved for any 
length of time over that metal. 

9. Iodine combines with the metals and forms substan- 
ces called iodides. 

PRACTICAL QUESTIONS. 

"What is iodine ? 
In what is iodine found ? 
How is it procured ? 
What are its properties ? 
Is iodine incombustible ? 

What is the phenomena of the action of iodine and ox- 
ides ? , 

What effect has carburet of sulphur on iodine ? 



£16 INTRODUCTION 

What is the effect of heating iodine and sulphur to 
getter ? 

What are iodides ? 



CHAP. XXIII. 

Of Salts in general. 
1. The term salt is usually employed to denote a 
compound in definite proportions, of acid matter, with 
an alkali, earth or metallic oxide. 

2. When the proportion of the constituents are so ad- 
justed that the resulting substance does not change the 
colour of litmus or red cabbage it is called a neutral salt. 

3. When the predominance of the acid is evinced by 
the reddening of those infusions, the salt is said to be 
acidulous, and the term super or bi is prefixed to indicate 
the excess of acid 

4. If the acid matter appears to be short of the quan- 
tity necessary for neutralizing the base, the salt is then 
said to be with excess of base, and the term sub is pre- 
fixed to the name. 

5. There are many substances known by the name of 
salts to which the above observations will not strictly ap- 
ply, as the muriates, prussiates, and fluates, for they con- 
tain neither acids nor alkaline bases. 

6. Only those acids which are compounds of oxygen 
and inflammable bases appear to enter into combination 
with the alkalies and alkaline earths, without alteration, 
and it is impossible to define the nature of the arrange- 
ment of the elements in their neutral compounds. 



TO CHEMISTRY. 217 

Observation. The phosphate and carbonate of lime 
have much less of the characters attributed to neutral sa- 
Ikie bodies, than chloride of calcium, muriate of lime, and 
yet this last body is not known to contain either alkaline 
or acid matter. 

7. The most important characteristic in salts is their 
solubility in water* In this they are usually crystallized, 
and by its agency they are purified and separated from 
one another. 

8. We may obtain a perfectly saturated solution of 
salts in the two following ways. 1. By heating the water 
with the salt and allowing it to cool to the temperature 
whose solubility is wanted. % By putting into cold water, 
a great excess of salt, and gradually elevating the tempe- 
rature. In each case it is requisite to keep the tempe- 
rature constant for at least two hours, and to stir the sa- 
line solution frequently, in order to make sure of its per- 
fect saturation. 

9. Saturation in a salme solution of an invariable tem- 
perature, is a point at which the solvent, always in con- 
tact with the salt, can neither take up any more, nor let go 
any more. 

10. Every saline solution which can part with salt 
without any change of temperature is supersaturated. 

11. In general supersaturation is not a fixed point. 
The cause which produces it, is the same which keeps 
water liquid below the temperature at which it congeals. 
That is, absolute rest, or the want of sufficient agita- 
tion. 

12. A salt that contains no water is said to be 
anhydrous. 

1 3. Salts that consist of an acid and two bases are 
called triple salts, and take the name of both bases. 

14. |,When the bases of a metallic salt contains an ex- 

19 



218 INTRODUCTION 

cess of oxygen, it is distinguished by the abbreviation' 
oxy, as oxy sulphate of iron. 

15. When salts are composed of acids ending in cm* 
they take a termination in ite instead of ate. 

Illustration. Lime combined with phosphorous acid., is 
called phosphite of lime, but when combined with the 
stronger, or phosphoric acid, it is called phosphate of 
lime. 

16. The general characteristics of the muriates are, — 
When heated, they melt and are volatilized. They are 
soluble in water. They effervesce with sulphuric acid, 
and white acrid fumes are disengaged. When mixed with 
nitric acid, they exhale the odour of chlorine. 

17. The general characteristics of sulphates are. 
They have a bitter taste. They are soluble in water 
but not in alcohol. Alcohol precipitates them from wat- 
er in a crystallized form. When heated to redness with 
charcoal, they are converted into sulphurets. 

Exp. Put a tea spoonful of sulphate of magnesia into 
some water, after it is dissolved, and the solution quite 
clear, add some alcohol to it, and the salt will be precip- 
itated. 

18c The carbonates are soluble in water. When sul- 
phuric acid is poured upon them, they effervesce violent- 
ly, emitting carbonic acid gas. 

19. The nitrates are characterized by their being 
soluble in water, and capable of crystallizing by cooling. 
When heated to redness with combustible bodies, a vio- 
lent detonation is produced. Sulphuric acid disengages 
red fumes from them. When heated with muriatic acid, 
chlorine is exhaled. 

20. The general characters of metallic salts are,— 
When they are strongly heated, they are volatilized and 



TO CHEMISTRY. 219 

dissipated. Hydro sulphuret of potash occasions a black 
precipitate from the solution. Muriatic acid when pour- 
ed into a solution of them in water, usually occasions a 
white precipitate. Gallic acid occasions a yellow pre- 
cipitate. A plate of copper plunged into a solution of 
mercurial salts, gradually precipitates running mer- 
cun r . 

21. When a warm solution of salt deposits on cool- 
ing, regular shaped masses, it is said to crystallize. These 
all differ in different salts, so that by knowing the form 
of the crystal, the class to which it belongs may be as- 
certained. 

Exp. Take half an ounce of Glauber's salt in crystals, 
dissolve it in the same quantity of hot water ; on cooling, 
crystals of the same shape will be formed. 

PRACTICAL QUESTIONS. 

What is the term salt usually employed to denote ? 

What is a neutral salt ? 

How do you express the excess of an acid in a salt ? 

How do you express the excess of base ? 

Do these observations apply to all substances known by 
the name of salts ? 

What acids appear to enter into the composition of al- 
kalies and alkaline bases to form salts ? 

What is the most important characteristic of salts ? 

What methods are used to obtain a complete saturated 
solution of salts ? 

What do you understand by saturation ? 

What is meant hy super saturation ? 

Is supersaturation a fixed point? 

When is a salt said to be anhydrous ? 

What are triple salts ? 



220 INTRODUCTION 

How is a metallic salt distinguished when its bas<g 
contains an excess of oxygen ? 

How are salts distinguished whose acids end in 
ous ? 

What are the general characteristics of the muri- 
ates? 

What are the characters of the sulphates ? 

What are the general characters of the carbonates I 

How are the nitrates characterized ? 

What are the general characters of metallic salts ? 

What is crystallization. 



CHAP. XXIV. 

Of Electricity, — Voltaic Electricity. 

1. Electricity is supposed to be a fluid which pervades 
almost all substances, and when undisturbed remains in a 
state of equilibrium. 

Observation. The phenomena produced by rubbing a 
piece of amber, constitutes the first physical fact record- 
ed in the history of the science. 

2. The certain portion which every body is supposed 
to contain is called its natural share, and so long as it con- 
tains neither more nor less than this quantity, it seems to 
produce no effect. 

3. When a body is by any means possessed of more 
or less than its natural share, it is said to be electrified or 
charged. 

4. If it possess more than its natural quantity it is, 
said to be positively electrified ; if it contain legs, nega- 
tively electrified 



TO CHEMISTRY 221 

5. Bodies through which the electric fluid passes 
freely, are called conducters, or non-elecwics. Those 
bodies which oppose the passage are called non-conduc- 
tors, or electrics. 

6. Two bodies, both positively, or both negatively 
electrified, repel each other, but if one body be positive 
and the other negative, they will attract each other. 

Exp. Take a small phial and rub it hard with a silk 
handkerchief, it will attract dust and other light substan- 
ces, when placed near them. 

7. When two bodies approach each other sufficiently 
near, one of which is electrified positively and the other 
negatively, the superabundant electricity rushes violently 
from one to the other, to restore the equilibrium between 
them. This effect takes place if the two bodies are con- 
nected by a conducting substance. 

8. The motion of electricity in passing from one body 
to another,, is so rapid that it appears to be instanta- 
neous. 

9. Electricity is produced by the mutual friction of all 
solid bodies, and of many fluids against solids, provided 
one of the bodies be of such a nature as to obstruct the 
speedy diffusion of the electric influence. 

10. The following is a list of conducting substances,^ 
arranged in the order of their conducting powers. 



1 Copper 


10 Plumbago 


2 Silver 


1 1 Strong acids 


3 Gold 


12 Soot and Lampblack 


4 Iron 


13 Metallic ores 


5 Tin 


14 Metallic oxides 


6 Lead 


15 Dilute acids 


7 Zinc 


16 Saline solutions 


8 Platinum 


17 Animal fluids 


9 Charcoal 


18 Sea water' 


19* 





222 INTRODUCTION 

19 Water 25 Vapour 

20 Ice & snow above 0° 26 Salts 

21 Living vegetables 27 Rarefied air 

22 Living animals 28 Dry earths 

23 Flame 29 Massive minerals, 

24 Smoke metallic. 

U. The following is a list of non-conductors, in the 
o$der of their insulating power. 



1 Shellac 


14 Baked wood and dryed 


2 Amber 


vegetables 


3 Resins 


15 Porcelain 


4 Sulphur 


16 Marble 


5 Wax 


17 Massive minerals, not 


6 Asphaltum 


metallic 



7 Glass and all vitrified 18 Camphor 
bodies, comprehending 19 Caoutchouc 
diamond and crystalliz- 20 Lycopodium 

ed transparent minerals. 21 Dry chalk and lime 

8 Raw silk 22 Phosphorus 

9 Bleached sihV 23 Ice below 0° F. 

10 Dyed silk 24 Oils, of which the dens- 

1 1 Wool, hair and feathers er are best 

12 Dry gases 25 Dry metallic oxides, in- 

13 Dry paper, parchment eluding fixed alkalies 
and leather and earthy hydrates. 

12. Electricity is excited in the fusion of inflammable 
bodies. 

Exp. If melted sulphur be poured into an insulated 
metallic cup, after it has become solid, the sulphur and 
cup will be both electrified ; the former positive, the 
latter negative. 

13. Electricity is~ produced by evaporation. 



TO CHEMISTRY. 223 

Exp. If we place a metallic cup on an electrometer, 
containing a small quantity of water, and plunge into it 
a red hot iron, the instrument will indicate electrical 
phenomena. 

14. Electricity is produced by the disengagement of 
gas. 

Exp. If into a platinum cup resting on the top of an 
electrometer, we put a little dilute sulphuric acid, and 
then throw in some iron filings, or chalk, when the effer- 
vescence increases, the instrument will indicate electri- 
cal phenomena. 

15. Electricity is produced by the tearing asunder ol 
solid bodies, probably owing to the friction among the 
particles. 

Exp. If we suddenly tear asunder pieces of mica, 
break across a stick of sealing wax, split up a piece of 
dry and warm wood, or scrape it with a piece of glass, 
the electrical equilibrium will be disturbed. 

16. Electricity is produced by contact of dissimilar 
bodies. 

Exp. If we take two flat plates, one of silver or cop- 
per, the other of zinc, each two or three inches in diam- 
eter, furnished with glass handles, and bring them into 
contact by their flat surfaces, we shall find on separating 
them, that they are both electrified. If we touch a cake 
of sulphur, gently heated, with the insulated copper 
plate, the effect will be more striking. Acid crystals, 
touched with metallic plates, indicate electrical phenom- 
ena. 

When crystals of oxalic acid are brought into contact 
with dry quicklime, electricity is developed. 

17. On the excitation of electricity by contact of dis- 
similar chemical bodies, is founded the principle of gal- 
vanic action, and the construction of the voltaic battery. 



224 INTRODUCTION 

18. Galvanism, or Voltaism, is occasioned, as appears, 
by the chemical action of bodies on each other. 

19. Galvanism, so named from the person who first 
promulgated it, appears to have been discovered by ac- 
cident. Galvani, a professor of natural philosophy, at 
Bologna, being engaged in some experiments on muscu- 
lar irritability, observed, that when a piece of metal was 
laid on a nerve of a frog, recently dead, whilst the limb, 
supplied by that nerve, rested on another piece of metal, 
the limb suddenly moved, on a communication being 
made between the two pieces of metal. 

20. This communication may be made, either by 
bringing the two metals into contact, or by connecting 
them by means of a metallic conductor. 

Exp. Take a piece of zinc, and place it under the 
tongue, and a piece of silver on the tongne, letting the 
metals project a little ; then make the projecting part 
of the metals touch each other, and a singular sensation 
will be produced. The effect is probably the same as 
that produced on the frog. 

21. Galvani supposed that the virtue of this new 
agent resided in the frog, but Volta, who paid particular 
attention to the subject, shewed that the phenomena did 
not depend upon those organs, but upon the electrical 
agency of the metals, which is excited by the moisture 
of the animal. Consequently, the saliva of the mouth 
answers the same purpose, and produces the sensation 
in the above experiment. 

22. It is not necessary that the fluids used in these 
experiments should be of an animal nature. Acids, very 
much diluted with water, are found to be the most effec- 
tual in the developement of electricity in metals ; and 
accordingly, the original apparatus, which Volta first 
constructed for this purpose, consisted of a pile, or sue- 



TO CHEMISTRY. 2 £5 

cession of plates of zinc and copper, each pair of which 
was connected by pieces of cloth or paper, moistened 
with water. This,, however, was found inconvenient, as 
well as of little power, which gave rise to the construc- 
tion of the present Voltaic battery. (Plate 3, fig. 3.) In 
this, the plates of zinc and copper are soldered together 
in pairs, each pair being placed at regular distances in 
wooden troughs, and the interstices filled with fluid. 

23. The action of the fluid on metals, whether water 
or acid be used, is entirely of a chemical nature. But 
whether electricity be excited by this chemical action, 
or, whether it be produced by the contact of the two 
metals, is a point upon which philosophers do not per- 
fectly agree. 

24. Volta and Sir H. Davy explain the action of the 
voltaic battery on the principle of the contact of the two 
metals ; but many philosophers entertain doubts on the 
truth of the theory. The principal difficulty is, that two 
such plates shew no signs of different states of electricity 
whilst together,but only on being separated, after contact. 
Now in the voltaic battery, those plates that are in con- 
tact, always continue so, being soldered together ; they 
cannot, therefore, receive a succession of charges. Be- 
sides, if we consider the mere disturbance of the balance 
of electricity, by the contact of the plates, as the sole 
cause of the production of voltaic electricity, it remains 
to be explained, how this disturbed balance becomes an 
inexhaustible source of electrical energy, capable of 
pouring forth a constant and copious supply of electrical 
fluid, though without any means of replenishing itself 
from other sources. 

The theory least liable to objection, appears to be that, 
first proposed by Dr. Bostock, called the chemical theory, 



226 INTRODUCTION 

This theorj r supposes the electricity to be excited by 
the chemical action of the acid upon the zinc. All met- 
als having a strong attraction for oxygen, and this ele- 
ment being found both in 'the water and the acid. The 
action of the diluted acid on the zinc, consists in .its oxy- 
gen, combining with the metal, and oxidating its sur- 
face. 

25. It appears that all metals are united with the 
positive electricity, and that oxygen is the source of the 
negative. 

26. In the galvanic action, the oxygen does not ap- 
pear to act on the copper, because the zinc has a strong- 
er affinity for oxygen than the copper ; the energy of 
the acid is, therefore, only exerted upon the zinc. 

27. If a plate of zinc be placed opposite to one of 
copper, or any other metal less attractive of oxygen, and 
the space between them, suppose of half an inch in thick- 
Bess, be filled with an acid, or any fluid capable of oxi- 
dating the zinc, the oxidated surface will have its ca- 
pacity for electricity diminished, so that a quantity of 
electricity will be evolved from the surface. This will 
be received by the fluid in contact ; by which it will be 
transmitted to the opposite metallic surface, the copper, 
which is not oxidated, and is therefore disposed to re- 
ceive it, so that the copper plate will become positive, 
while the zinc plate will be in the negative state. 

Observation. This evolution of electricity will be very 
limited, for as these two plates admit of but very little 
accumulation of electricity, and are supposed to have 
none with other bodies ; the action of the acid, and 
farther developement of electricity will be immediately 
stopped. 

28. In order that the acid may act freely on the zinc, 
and the two electricities given out without interruption, 



TO CHEMISTRY. 227 

some method must be devised by which the plates may 
part with their electricities as they receive them. If 
the wires connected with either plate are made to meet, 
the two electricities will then be brought together, and 
will combine and neutralize each other, as long as this 
communication continues ; the two plates will dispose of 
their respective electricities, and the action of the acid 
will be continued. 

29. The intensity of the electricity is increased by 
increasing the number of plates. If we take four plates, 
two of zinc, and two of copper, placed alternately in a 
trough, filled with diluted nitrous acid, and the two cen- 
tral ones be soldered together, as in the voltaic battery, 
so as to form but one plate, two dissimilar surfaces will 
be afforded, the one of copper, the other of zinc. Now 
a quantity of electricity being evolved from the first 
zinc plate, in consequence of the action of the acid, is 
conveyed by the interposed fluid to the copper plate, 
which thus becomes positive. This copper plate com- 
municates its electricity to the zinc plate, to which it is 
joined, in which some communication of electricity takes 
place. When, therefore, the fluid in the next cell acts 
upon the zinc plate, electricity is extricated from it, in 
larger quantity, and in a more concentrated form than 
before. This concentrated electricity is again conveyed 
by the fluid to the next pair of plates, when it is further 
increased by the action of the fluid in the third cell, and 
so on to any number of plates of which the battery may 
consist ; so that the electrical energy will continue to 
accumulate, in proportion to the number of double plates ; 
the first zinc plate of the series being the most negative, 
and the last copper one, the most positive. 

30. If the battery remain undisturbed, the action will 
soon stop, unless so'me vent be given to the accumulated 



£28 INTRODUCTION 

electricities. This is easily done, however, by estab- 
lishing a communication by means of the wires (plate 3, 
fig. 3,) between the two ends of the battery ; these be- 
ing brought into contact, the two electricities meet, and 
neutralize each other, producing the shock and other 
phenomena of electricity ; and the action goes on with 
renewed energy, being no longer obstructed by the ac- 
cumulation of the two electricities. 

31. The great superiority of the voltaic battery con- 
sists in the large quantity of electricity which passes ; 
but in regard to the rapidity or intensity of the charge, 
the common electrical machine greatly surpasses it. It 
appears that the shock or sensation depends chiefly upon 
the intensity ; whilst on the contrary, for chemical pur- 
poses, it is quantity which is required. In the voltaic 
battery, the electricity though copious, is so weak as not 
to be able to force its way through the fluid which sepa- 
rates the plates j whilst that of a common machine will 
pass through any space of water. 

32. The action of the voltaic battery may actually 
be increased, until it equals a weak electrical machine, 
so as to produce a visible spark when accumulated in a 
Leyden jar. But it can never be raised sufficiently to 
pass through any considerable extent of air, because of 
the ready communication through the fluids employed. 

33. The intensity is increased by increasing the num- 
ber of plates of a battery, whilst by enlarging the dimen- 
sions of the plates, the quantity is increased ; and as the 
superiority of the battery over the common electrical 
machine, consists entirely in the quantity of electricity 
produced, it was at first supposed that it was the size, 
rather than the number of plates, that was essential to 
the augmentation of power. It was, however, found by 
experiment, that the quantity of electricity produced by 



TO CHEMISTRY, 222 

the voltaic battery, even . when at the rate of a very 
moderate size, was sufficiently copious, and that the chief 
advantage in this apparatus was obtained by increasing 
the intensity, which, however, still falls short of that, 
ef the common machine. 

34. A battery may be formed to shew the galvanic 
effect on a small scale, in the following manner. It con- 
sists of a row of cups or tumblers, containing salt and 
water, or nitrous acid and water. Into each of these, is 
plunged a plate of zinc, and another of copper. These 
plates are made to communicate with each other by 
means of a thin platina wire, fastened so that the copper 
of the first glass is connected with the zinc of the sec- 
ond, the copper of the second with the zinc of the third, 
and so on through the whole row of glasses ; when one 
hand is dipped into the first glass, and another in the 
last, the shock is perceived. But this battery is not con- 
venient, on account of the great space which it must 
necessarily occupy. 

35. The battery of the royal institution, (London) 
constructed by Mr. Children, is the most powerful in the 
world, in calorific effect. It consists of 2000 pairs of 
plates, of 32 inches each, exposing a surface of 128,000 
square inches. This battery, when the cells were filled 
with 60 parts of water, mixed with one part of nitric 
acid, and one of sulphuric acid, afforded a series of bril- 
liant and impressive effects. 

Exp. 1 . When pieces of charcoal, about an inch long, 
and one sixth of an inch in diameter, were brought with- 
in l-80th or l-40th of an inch of each other, a bright 
spark was produced, and more than half the volume of 
charcoal was ignited to whiteness, and by drawing back 
the points a little from each other, a constant discharge 
took place, through the heated air, in a space equal at 
20 



230 INTRODUCTION 

least to four inches, producing a most brilliant ascending 
arch of light, expanded and conical in the middle. When 
any substance was introduced into this arch, it instantly 
became ignited. 

Exp. 2. Platinum melted in it, like wax in the flame 
©f a common candle. Likewise quartz, sapphire, mag- 
nesia and lime. Fragments of diamond, and points of 
charcoal and plumbago, rapidly disappeared, and seemed 
to evaporate in it, even when the connection was made 
in an exhausted receiver, but there was no evidence of 
their previously having undergone fusion. 

36. When the communication between the points, 
positively and negatively electrified, was made in air 
rarefied in the receiver of an air pump, the distance at 
which the discharge took place increased as the exhaus- 
tion proceeded, and when the atmosphere in the vessel 
supported only an inch of mercury in the barometrical 
gauge, the spark passed through a space of nearly half 
an inch. By making the points recede from each other, 
the discharge was made through 6 or 7 inches, produc- 
ing a most beautiful coruscation of purple light ; the 
charcoal became intensely ignited, and some platinum 
wire attached to it, fused with beautiful scintillations, 
and fell in large globules on the plate of the pump. AH 
the phenomena of chemical decomposition were produc- 
ed with intense rapiditj^, by this combination. 

Exp. When the points of charcoal were brought near 
each other in non-conducting fluids, such as oils, ethers, 
and chloriodic compounds, brilliant sparks occurred, and 
elastic matter was generated. 

37. There are no fluids known except such as con- 
tain water, which are capable of being made the medium 
of connexion between the metals, or metal of the voltaic 
apparatus ; and it is probable that the power of water 



TO CHEMISTRY. 231 

to receive double polarities, and to evolve oxygen and 
hydrogen is necessary to the constant operation of the 
connected apparatus. 

38. It is probable that acids, or saline substances, in- 
crease the action of the battery, by affording elements 
which possess opposite electricities to each other when 
mutually excited. 

39. The following simple experiment shews the man- 
ner in which aqueous fluids propagate electrical polarity 
among their particles. Cut narrow filaments of tin foil 
into lengths of almost half an inch, and place them in a 
line on the surface of an oblong trough of water. Oa 
plunging into the water at each end, wires connected 
with the two extremities of an active voltaic battery, 
the metallic filaments will immediately acquire polarity. 
Their positive and negative poles will become regular- 
ly opposed to each other, the first depositing oxide, and 
the last evolving hydrogen. The analogy with magnetic 
actions is here very complete. 

40. That the decomposition of the chemical agents 
is connected with the energies of the pile, is evident 
from all the experiments that have been made. No 
sound objection has been urged against the theory, that 
the contact of the metals destroys the electrical equili- 
brium, that the chemical changes restore it, and, conse- 
quently, that the action exists as long as the decomposi- 
tion continues. 

41. Salts, as well as other substances, may be decom- 
posed by electricity, and their elements thus ascertain- 
ed. 

42. If we dissolve a quantity, however small, of any 
salt, in a glass of water, and plunge into it the extremi- 
ties of the wires which proceed from the two ends of 
the voltaic battery, the salt will be gradually decoi* 



£32 INTRODUCTION 

jposed, the acid being attracted by the positive, and ther 
alkali by the negative wire. If pieces of paper, stained 
with certain vegetable colours, which are altered by the 
contact of an acid, or an alkali, be placed in the glasses, 
the colours will be changed, agreeably to the above 
pherromeBav 

Illustration Blue vegetable preparation of litmus be- 
comes red, when touched by an acid ; and the juice of 
violets becomes green by the contact of an alkali. 

43; The experiment can be made in a much more 
distinct manner, by receiving the extremities of the wires 
into two vessels, so that the alkali shall appear in one 
vessel, and the acid in another. 

44, Let the two vessels be connected together by 
some interposed substance, capable of conducting elec- 
tricity, as a piece of moistened cotton thread. Plate 4, 
fig. 2. c. Put into each of the glasses, a little sulphate 
of soda, which consists of an acid and an alkali, then fill 
the glasses with water, which will dissolve the salt. — 
Now connect the glasses by means of the wires, e. d. 
with the two ends of the battery. Bubbles soon begia 
to rise from the decomposition of the water. In order 
to render the separation of the acid from the alkali visi- 
ble, pour into the glass, a. which is connected with the 
positive wire, a few drops of a solution of litmus, and 
into the other glass, b. which is connected with the neg- 
ative wire, a few drops of the syrup of violets. The lit- 
mus immediately begins to turn red, and the violet solu- 
tion, green. 

Exp. 1. Take three glasses, plate 4, fig, 3, a. b. c. 
connected together by wetted cotton, but the middle one 
only contains a saline solution, the two others containing 
distilled water, coloured as before, by vegetable infu- 
sions : vet on ^nakin? the connection with the battery, 



;|jF. WW? WW WW WMjV«(W vVW WW v WV wvv% vw% VW^ W^WWWVVW WW WW t* 




co go i 



r* G4 CO 



f WWVW\ VW*'V*V> WW VWX'WVX'W^'X'VWX "VW* VW\ 1 



TO CHEMISTflV, 233 

the alkali will appear in the negative glass c. and the 
acid in the positive glass a. though neither of them con- 
tained any saline matter. The acid and alkali are con- 
veyed right and left, from the central glass. 

45. Voltaic electricity is of extensive use in chemis- 
try. It has, of late years, brought to light many impor- 
tant facts, a knowledge of which, would probably never 
have been obtained, independent of this powerful agent/ 

PRACTICAL QUESTIONS. 

What is electricity ? 

What is called the natural share of a body ? 

When is a body said to be electrified or changed ? 

When is it positively and negatively electriried ? 

What are called conductors and non-conductors ? 

When do bodies repel each other ? 

What is the effect when two bodies approach each 
other, the one being positively, and the other negatively 
electriried ? 

How great is the motion of electricity ? 

How is electricity produced ? 

What are the conducting substances ? 

What are the non-conducting substances ? 

Is electricity ever excited by fusion ? 

Illustrate it. 

Is electricity produced by evaporation ? 

Illustrate it. 

Does the disengagement of gas produce it ? 

Illustrate it. 

Does the tearing asunder of solid bodies produce it ■?•■' 

Illustrate it. 

Is electricity produced by contact ? 

Illustrate it. 

What principle is founded on this ? 
20* 



f 


<&*«* r*I **We of $H 


f&uKgf* 




1 

I 




Sp. gr. 


Precipitants. 




ecipitates by 

Hydrosulphur 




NAMES. 


Ferroprussiate 


I n f us i on f gap. 


- Sulphuretted 5 


\ 






of potash. 




ets. 


1 vorogen. 


I 


', i Platinum 


21.47 


Mur ammon. 










Bi'k. met.pow 


\ 2 Gold 


19.30 


( Sulph Iron 
i Nit.mercur 


Yel' wish white 


Green ; met. 


Yellow 


Itellow i 


\ 3 Silver 
', 4 Palladium 






White 


Yellow-brown 


Black 


Black I 


11.8 


Prus. mercury 


Deep orange 




Blackishbrow 


3 Black-brown ; 


\ 5 Mercury 


13.6 


Common salt 
Heat 


White passing 
to yellow 


Orange yellow 


Brownish bPc 


i Black • 


\ 6 Copper 


8.9 


Iron 


Red-brown 




Black 


Do. 






Blue, or white 


Perox. 


Black 

Pro tor. black 

Perox. yellow 


5 


| 7 Iron 


7.7 


with peros. 


passing to blue 


Perox-black 


° i 


| 8 Tin 


7.29 


Corr. sublim 


White 





Brown \ 


I 9 Lead 


11.35 


Sulph soda 


Do. 


White 


Black 


Black \ 
I 


JlO Nickel 


8.4 


Sulph. potash? 


Do. 


Grey-white 


Do. 


hi Cadmium 


8.6 


Zinc 


Do. 





Orange yellow 


p Orange yellow 5 


J 12 Zinc 


6.9 


Alk.carbonates 


Do. 





White 


Yel'wislnvhite £ 


j 13 Bismuth 


9.88 


Water 
S Water 


Do. 
With dilute so- 


Yellow 
White from 


Black-brown 


Black brown f 


< 14 Antimony 


6.70 


Jzinc 


lutions,white 


water 


Orange 


Orange ? 


J 15 Manganese 


8. 


Tartr. Pot. 


White 





White 


Milkiness 1 


| 16 Cobalt 


8.6 


Alk.carbonates 


Brown yellow 


Yellow white 


Black 


I 


; 17 Tellurium 
J 


6.115 


< Water 
I Antimony 





Yellow 


Blackish 


! 

1 


I 18 Arsenic 


i 8.35 ? 
1 5.76 ? 


Nitr. lead 


White 




Yellow 


Yellow 5 


19 Chromium 


5.90 


Do. 


Green 


Brown 


Green 


5 


20 Molybde'm 


8.6 


Do? 


Brown 


Deep brown 




Brown ; 


21 Tungsten 


17.4 


Mut. lime? 


Dilute acids 






[ 


22 Columbium 


5.6? 


Zincorinf.gals 


Olive 


Orange 


Chocolate 


J 


23 Selenium 


4.3? 


( Iron 

( Sulphite am. 










24 Osmium 




Vlercury 




Purple passing 
to deep blue 








25 Rhodium 


10.65 


Zinc? 












26 Iridium 


18.68 


Do? 















27 Uranium 


9.0 


Ferroprus.pot. 


Brown-red 


Chocolate 


Brown-yellow 

Grass-green 

White 







28 Titanium 

29 Cerium 




Inf. galls 
Oxal amm. 


Grass-green 

Milk-white 


Red brown 








30 Wodanium 


11.17 


Zinc 


Pearl-grey 











31 Potassium 


0.865 


< Mur plat. 
1 Tart, acid 
















32 Sodium 


0.972 














33 Lithium 
















34 Calcium 












1 




35 Barium 












j 


36 Strontium 












i 


37 Magnesium 












\ 


38 Yttrium 












i 


39 Glucinum 












l 


40 Aluminum 












i 


■U Thurimm, 
18 Zirconium 












I 


13 Siticiuui 












I 





£34 INTRODUCTION 

How is? galvanism occasioned ? 
Haw was it discovered ? 
How may the communication be made ? 
Illustrate by an experiment. 
Where does the agency reside ? 
Must the fluids used, be of an animal nature ? 
Of what nature is the action of the fluid ? 
What is supposed to be the cause of the action of the 
voltaic battery ? 

What is the theory least liable to objection ? 
W T hat is the source of the positive and negative elec- 
tricity ? 

Why does not the oxygen act on the copper in the 
galvanic battery ? 

What will be the effect, if a plate of zinc be placed 
opposite to one of copper, and the space between them 
filled with any fluid ? 

What is necessary in order that the two electricities 
may be given out without interruption ? 

How do you increase the intensity of electricity ? 
If the battery remain undisturbed, will the action stop ? 
In what does the grreat superiority of the voltaic bat- 
tery consist ? 

Can the electricity of the voltaic battery be collected 
in a Leyden jar ? 

How may the quantity of electricity be increased ? 
How can you shew the action of the voltaic battery on 
a small scale ? 

Describe the battery of the Royal Institution. 
Rehearse some experiments. 

What fluids are capable of being made the medium of 
■• communication ? 

On what principle do acids or saline substances act ? 



TO CHEMISTRY. 235 

How do you shew electrical polarity among aqueous 
particles ? 

With what is the decomposition of chemical agents 
connected ? 

How can salts be decomposed by electricity ? 

Relate the different methods. 

k voltaic electricity of any use ?• 



CHAP. XXV. 

Of Metals. 

1. Metals are the most numerous class of undecom* 
pounded chemical bodies ; and are distinguished by the 
following properties. 1 . They possess a peculiar lustre, 
which continues in the streak,- and in their smallest frag- 
ments. 2. They are fusible by heat, and in fusion, re* 
tain their lustre and opacity. 3. Except selenium, they 
are all excellent conductors of caloric and electricity. 
4. Many of them may be extended under the hammer, 
and are called malleable ; cr under the rolling press, and 
are called laminable ; or drawn into wire, and are called 
ductile. 

Observatio?i. This capability of extension, depends in 
some measure, on a tenacity peculiar to the metals, and 
which exists in the different species with very different 
degrees of force. 

2. When the saline combinations of the metals are 
electerized, the metal separates at the negative pole. 

3. When exposed to the action of oxygen, chlorine, 
or iodine, at an elevated temperature, they generally 



23 INTRODUCTION . 

take fire, and combining* with one or other of these three 
elementary solvents in definite proportions, are con- 
verted into saline or earthy looking bodies, void of me- 
tallic lustre and ductility, called oxides, chlorides, or io- 
dides. 

4. They are capable of combining in their melted 
state, with each other, in almost every proportion, con- 
stituting the important order of alloys, in which the char- 
acteristic lustre and tenacity are preserved.. 

5. From their brilliancy and opacity, they reflect the 
greater part of the light which falls on their surfaces ; 
in consequence of this property they form excellent mir- 
rors for telescopes and other purposes. 

6. Most of them combine in definite proportions 
with sulphur and phosphorus, forming bodies frequently 
of a s^mi-metallic aspect, others unite with carbon, hydro 
gen and borax, giving rise to peculiar gaseous or solid 
compounds. 

7. Many of the metals are capable of assuming, by- 
particular management, crystalline forms, which are, for 
the most part,, either cubes or octahedrons. 

8. The metals have been variously classed by differ, 
ent ehemists ; it is a task of no small difficult}'. The 
following is the arrangement of Dr. Ure, of Glasgow. 
It commences with those metals which possess the obvious 
qualities of unalterability by common agents ; tenacity and 
lustre. This order indicates very nearly, their relations 
to oxygen; and as we descend the series, the influence 
of that element increases. Among the substances near 
the head, powers of oxygen are subjugated by the metal- 
lie constitution, but among those near the bottom, it is 
very predominant, which the pile of Voita can only 
disengage; but the metal soon re-unites with oxygen. 



TO CHEMISTRY. 237 

9. The first twelve, together with the 31st, 32d, and 
33d, are malleable. 

10. The first 16 yield oxides which are neutral sal- 
ifiable bases. 

11. The metals, 17, 18, 19, 20, 21, 22 and 23, aTe 
acidifiable by their combining with oxygen. The remain- 
ing ones from the 31st form with oxygen, the alkaline and 
earthy bases. The oxides of those from the 23d to the 
31st are but little kuown. 

12. Metallic alloys may be analyzed in the following 
manner, which is a beautiful experiment to show the or- 
der of affinities. 

Exp. Take an alloy composed of silver, copper, lead, 
bismuth and tin. Let it be dissolved by the aid of heat 
in an excess of nitric acid, of the specific gravity 1 .23, 
Evaporate the solution almost to dryness and pour 
water on the residuum. We shall thus obtain a solution 
of silver, copper and lead, while the oxides of bismuth 
and tin will be precipitated. By exposing this precipi- 
tate to the aetion ©f nitric acid, the oxide of bismuth will 
be separated from that of tin. To determine the propor 
tions of the other metals, pour, first, into the hot and 
pretty diluted-solution, muriatic acid, which will throw 
down the silver. After filtration, add sulphate of soda to 
separate the lead ; and finally carbonate of potash to pre- 
cipitate the zinc. The quantity of each metal may now 
be deduced from the weight of each precipitate, accord- 
ing to its specific nature. 

PRACTICAL QUESTIONS. 

How are metals distinguished ? 

What is the consequence of electerizing the saline 
combinations of the metals ? 

What is the effect of exposing them to the action of oxy- 
gen, chlorine and iodine ? 



2SB : INTRODUCTION 

Are they capable of ccmbining with each other? 

Is their brilliancy and opacity of any use ? 

Do they combine with sulphur and phosphorus T 

Do they ever assume a crystalline form ? 

How are the metals classed ? 

Name the metals and their specific gravities ? 

Which of them are malleable ? 

Which are acidifiahle ? 

Give an example of analysis ? 



CHAP. XXVI. 

Of P latinum — Go Id — Sih er — Pa lladium — Me rcury. 

1. Platinum or Platina, in the Spanish language, sig- 
nifies little silver. It is of a greyish colour, almost black 
when polished, insipid, inodorous, softer than iron, and 
less ductile than Gold. It is the heaviest of all metals 
hitherto discovered. 

2. It is most difficult of fusion, for this purpose 
it requires a degree of heat equal to about 175° of 
Wedgwood, or 11560 Farenheit. It readily conducts 
electricity. — It is unalterable in the air. 

3< Muriate of tin i* a delicate test of platinum. 

Exp. 1. A single drop of the recent solution in muri- 
atic acid, gives a bright red colour to a solution of muri- 
ate of platinum scarcely distinguishable from water. 

Exp. 2. If the muriatic solution of platinum be agita- 
ted with ether, the ether will become impregnated with 
the metal. It is of a tine pale yellow, does not stain the 
skin, and may be precipitated by ammonia. 

Exp. 3, If the muriatic solution of platinum be pre* 



TO CHEMISTKY. £39 

cipitated by lime, r and the precipitate digested in sulphur, 
ic acid, a sulphate of platinum wiU be formed. 

4. Platinum does not edmbine with sulphur directly, 
but is soluble by the alkaline sulphurets, and precipitable 
from its nitro muriatic solution by sulphuretted hydro- 

5. Platinum may be united with phosphorus by pro- 
jecting small bits of phosphorus on the metal heated to 
redness, in a crucible, or by exposing to heat four parts 

each of concrete phosphoric acid, and one of charcoal 
powder. 

6. The phosphuret of platinum is of a silvery white, 
very brittle and sufficiently hard to strike fire with steel. 
•It is more fusible than the metal itself, and a strong heat 
expels the phosphorus. 

7. Platinum unites with most other metals. 

Exp. Added in the proportion of 1 12th to gold, it forms 
a yellowish white metal, highly ductile, and of considera- 
ble tenacity, having the spcific gravity of 19.013. 

8. Platinum renders silver harder, but its lustre 
duller. 

9. Copper is much improved by alloying with pla- 
tinum. 

Exp. If l-6th or l-25th be added to copper, it be- 
comes of a golden yellow colour, much harder, of a finer 
polish, smoother grained and much less liable to rust. 

10. There are two oxides of platinum, the protoxide 
which may be obtained b} r pouring a solution of neutral 
nitrate of mercury into a dilute solution of muriate of 
platinum. A dark brown, or olive green precipitate is 
formed, which must be well washed and heated, so as td 
expel the mercury. 

The protoxide consists of 

Platinum, 100.00 
Oxygen, 4,423 



£40 INTRODUCTION" 

11. The peroxide appears to contain three prime 
proportions. It is obtained by treating the muriate of 
.platinum with sulphuric acid at a distilling heat, and de- 
composing the sulphate with aqua potassae. It is a yel- 
lowish brown powder, easily reducible at a red heat, to 
the metallic state. 

12. It unites with chlorine in two proportions, form- 
ing the proto chloride and the bichloride. The former 
is soluble in water, while the latter is insoluble. 

The bichloride appears to consist of 

Platinum, 100 or 1 prime 23.73 
Chlorine, 27.932. 9.00 

13. The salts of platinum have the following general 
characters. 1. Their solution in water is yellowish 
brown. 2. Potash and ammonia determine the formation 
of small orange coloured crystals. 3. Sulphuretted hy- 
drogen throws down the metal in a black powder. 4. 
Ferroprussiate of potash and infusion of galls occasion no 
precipitate. 

14. Fulminating Platinum is formed in the following- 
manner. Into a solution of the sulphate in water, aque- 
ous ammonia is poured, and the precipitate which falls 
being washed,is put into a matrass with potash le}',and boiL 
-ed for some time. It is then filtered, washed and dried. A 
brown powder is obtained, which is the fulminating pla- 
tinum. It explodes violently when heated to 400° ; but 
does not detonate by friction or percussion. It is a non- 
conducter of electricity. With sulphuric acid it forms a 
deep coloured solution. Chlorine and muriatic acid gas 
.decompose it. 

15. From its hardness, infusibility, and difficulty of 
being acted upon by most agents, platinum is of great use 
in the fabrication of many chemical utensils. 



TO CHEMISTRY. 241 

16. Gold is a yellow metal, very soft, ductile, tough 
and malleable, unalterable and fixed in the air, or the 
strongest heat of a furnace. The electric shock converts 
it into a purple oxide. It melts at 32°, W. Its colour, 
when melted, is of a bluish green, and the same colour 
is exhibited when light is transmitted through gold leaf. 
Its ductility is so great that it may be beaten into leaves 
of -os 2V Co P ar * °f an mG k m thickness. 

17. It is soluble in nitro-muriatic acid and aqueous 
chlorine. 

1 8. Gold may be precipitated from its solution by lime, 
-magnesia and the alkalies. 

1 9. There is a strong affinity between the oxide of 
Gold and muriatic acid. The theory of its solution is the 
nitric acid of the nitro-muriatic furnishes oxygen soon as 
to the gold, and the muriatic acid dissolves that oxide as 
formed. 

20. There are two oxides of gold, the protoxide which 
is of a purple colour, and the peroxide which is yel- 
low. 

These may be decomposed by heat. 
The protoxide seems to consist of 100 metal + 4 os> 
ygen. 

The peroxide of 100 metal -f 12 oxygen. 

The prime equivalent of gold appears to come out 25. 

21. Gold combines with a great number of metals and 
forms with them a variety of alloys. It will combine al- 
so with phophorus, forming w T ith it a phosphuret of gold, 
which is brittle, whitish, and has a cyrstallized appear- 
ance. 

Exp. 1. A leaf of Gold introduced into a jar of chlo. 

fine will take fire and burn. 

Exp. 2. Solution of gold gives a purple colour to the 
21 



242 INTRODUCTION 

skin. It is used for staining ivory, feathers, porce- 
lain, &c. 

Exp. 3. The oxide of gold combined with ammonia 
makes fulminating gold, which explodes with great vio- 
lence by means of heat. 

Exp* 4. Ribands moistened with the dilute solution 
of gold, and exposed to a current of hydrogen gas, will 
be gilt. By means of a camePs hair pencil, dipt in the 
solution and applied to different parts of the ribands, fig- 
ures in gold may be given to them which will be veiy 
permanent. 

Exp- 5. A sheet of tin immersed in a solution of gold, 
precipitates the gold of a purple colour, which, when col- 
lected, forms a powder much used in enamelling. 
Exp. 6. If ether be added to a solution of muriate of gold, 
the gold will leave the acid and float on the surface, com- 
bined with ether. 

22. Green sulphate of iron is a good test for 
gold. 

Exp. To a solution of gold add a solution of sulphate 
of iron, a precipitate will be formed of a brown 
colour. 

23. Mercury has a strong affinity for gold,with which 
it unites in all proportions and forms an amalgam, which 
is softer the larger the proportion of mercury. 

24. Gold coins and medals are alloys of gold and cop- 
per, and in all cases the degree of purity of the gold is 
expressed by the number of parts of that metal contained 
in twenty-four parts of any mixture. 

Illustration. Gold, which in twenty-four parts called 
carats, contains twenty-two of pure metal, is said to be 
twenty-two carats fine, and absolutely pure gold is said to 
be twentv-four carats fine, 



TO CHEMISTRY. 243 

25. Silver is the whitest of all metals. It is harder 
than gold, very ductile and malleable, but less so than 
gold, silver leaf is more than one third thicker than gold ; 
in this state it does not transmit light. It ignites before 
melting, and requires a strong heat to fuse it. 

It is vitrified by the heat of a very powerful lens. 

26. In the electric circuit of a powerful galvanic bat- 
tery, silver leaf may be made to burn with a beautiful 
green light. 

27. The air has very little effect on it, though it ob- 
tains a purple or black coating in contact with sulphur- 
eous vapours, which are emited from animal substances in 
a state of decomposition. This coating is found to be a 

jtalphvret of silver. 

28. There seems to be only one oxide of silver, 
which is formed by intense ignition in an open vessel, 
when an olive coloured glass is obtained,, or by adding a 
solution of caustic barytes to one of nitrate of silver, and 
heating the precipitate to dull redness. It consists of 100 
silver and -\-l. 3 oxygen. 

29. Silver combines with chlorine, and was formerly 
called luna cornea, or horn silver. It may be formed by ad- 
ding a solution of muriate of soda to one of nitrate oi 
silver. 

30. Fulminating powder may be formed with silver, 
which may be very terrible in its effects. It is made by 
pouring lime water into a solution of the pure nitrate and 
filtering, washing the precipitate, and then digesting on 
it liquid ammonia for twelve hours. The ammonia must 
be cautiously decanted from the black powder, which is 
to be dried in minute portions, and with great caution, 
an bits ojf filtering paper or card. 

31. If struck, eveain its moist state with a hard body- 



S44 INTRODUCTION 

it explodes ; and if in any quantity when dry,the fulmiha- 
tion is tremendous. 

32. If the decanted ammonia be gently heated, it effer- 
verces from disengagement of azote, and small crystals 
appear in it when it cools. These possess a still more- 
formidable power of detonation, and will scarcely bear 
touching even under the liquid* it appears to be a com- 
pound of oxide of silver and azote*, 

33. The sudden extrication of the condensed gas is the^ 
cause of $te detonation^ 

34. Silver is soluble in sulphuric acid at a boiling heat, 
when concentrated. Nitric acid dissolves more than 
half its weight of silver. It destroys and corrodes animal 
substances very powerfully. When crystallized, melted 
and east into sticks it forms the Lunar caustic of the 
shops. 

35. Nitrate of silver ma}' be decomposed by other 
metals ; a plate of copper to which it is applied becomes 
plated with silver. 

Exp. Spread a few drops of nitrate of silver upon a 
piece of window glass by means of a camel's hair pencil ; 
at the bottom of it in contact with the fluid, place a small 
brass or copper wire ; let it remain undisturbed; and in a 
short time, it will begin to shoot into apparent vegeta* 
tion. 

36. For silvering of dial plates, scales of barometers, 
thermometers, &c. The muriate of silver is chiefly 
used, from which the silver is precipitated and unites with 
the coppery surface. 

27. A useful solvent of silver is formed by dissolving 
one part of nitrate of potash, by weight in eight or ten 
parts of concentrated sulphuric acid. This compound 
Galled nitro-sulphuric acid, when heated below the tem- 
perature of boiling water, dissolves a sixth or even a fifth 



TO CHEMISTRY. 245 

of its weight of silver, with an extrication of nitrous gas, 
and leaves the copper or other metal with which the sil- 
ver may be combined. This is of great use in extracting 
silver from plated articles. 

38, The beautiful representation called Diana's tree r 
may be made in the following manner. Take three 
drams and a half of pure silver, and half as much mer- 
curj r ; dissolve them separately in sufficient quantities of 
pure nitric acid, then mix the solution and add to them 
rive or six ounces of distilled water. This is to be pour- 
ed upon rather less than half an ounce of an amalgam of 
silver, which is put into a spherical glass vessel. In the 
course of twenty four hours the silver tree will be form- 
ed. 

39. Silver is found in various parts of the world, 
in a metallic state, a suiphuret and an oxide. 

EXPERIMENTS. 

1. Add a few drops of muriatic acid to some nitrate 
of silver, a white curdy or flaky precipitate falls down in 
great abundance, this precipitate is decomposed by light, 
for if exposed to the direct rays of the sun, its colour be- 
comes darker. 

2. if one part of muriate of silver be mixed with three 
parts of carbonate of soda and fused in a crucible, the sil- 
ver will be reduced and found at the bottom of the cruci 
bie. 

3. A solution of the nitrate of silver stains animal sub- 
stances of a deep black : It has been applied to the stain- 
ing of the human hair. 

4. White paper when stained with a solution of nitrate 
of silvcryin the proportion of ten parts of water and one 



2! 



* 



246 introduction 

of the salt, and exposed to the light, acquires colour and 
passes through ail the changes to black. 

5. Let a slip of ivory be immersed in pure nitrate of 
silver, till it acquires a bright yellow colour ; then re- 
move it into a glass of distilled water, and expose it to 
the direct light of the sun ; it will, after two or thre^ 
hours, become black, but on rubbing it a little, the sur- 
face will be changed into a bright metallic one. 

40. Palladium is a new metal first found by Dr. Wol- 
laston, in ores of Platina. It is scarcely distinguished from 
the crude platina, though much harder. 

41. Palladium is of a greyish white colour and takes 
a good polish. It is ductile and very malleable ; and. be- 
ing reduced into thin strips is flexible, but not very elas- 
tic. Its fracture is fibrous, and in diverging striae, ex- 
hibiting a kind of crystalline arrangement. In hardness 
it is superior to wrought iron. It is a less perfect conduc- 
tor of caloric than most metals, and less expansible, 
though in this it exceeds platina. On exposure to a 
strong heat its surface tarnishes a little and becomes blue, 
but an increased heat brightens it again. It requires 
more heat than that of gold for its fusion, but if touched 
when hot with a small bit of phophorus, it runs like zinc. 
The sulphuret is whiter than the metal itself, and ex- 
tremely brittle. 

42. It is soluble in nitric acid, which soon acquires a 
fine red colour, but the quantity dissolved is small. Ni- 
trous acid acts on it more quickly and powerfully. Sul- 
phuric acid by boiling, acquires a similar colour, dissolv- 
ing a small portion. Muriatic acid acts much in the same 
manner. Nitro-muriatic acid acts upon it powerfully, 
and assumes a deep red. 

43. Alkalies and earths throw down a precipitate of a 
fine orange colour. Recent muriate of tin precipitates 



TO CHEMISTRV, 247 

it of an orange or brown colour, or a beautiful emerald 
green. Green sulphate of iron precipitates the palladi- 
um in a metallic state. Sulphuretted hydrogen, dark 
brown. All the metals, except gold, silver and platina. 
precipitate it in a metallic state. 

44. Mercury has derived several names from its sim- 
ilarity to silver ; as quicksilver, argentum vivum^ and hy- 
drargyrum. 

45. It is distinguished from all other metals, by its 
extreme fusibility ; it is not solid until cooled down to 
the 39 — of Farenheit ; of course, it is always fluid in 
our climate. Its colour is white, and rather bluer than 
silver. In the solid state, it is malleable. It is volatile, 
and rises in small portions in the common temperature 
of the atmosphere. It boils at the temperature of 656°. 
When exposed to a heat of 600°, it gradually acquires 
oxygen, and is converted into a red powder, or oxide, 
which is said to be the tritoxide. This was formerly 
known by the name of precipitate per se. From its vola 
tility, it is commonly purified by distillation. 

46. There have been reckoned three oxides of mer- 
cury. 1. The protoxide, when, the mercury is con- 
verted into a black powder by agitation, formerly called 
ethiops per se. 2. When it is dissolved ia nitric aeid with- 
out the assistance of heat, the deutoxide is formed. — 
v 3. When exposed to the heat of 600° for a considerable 
length of time, the peroxide is formed. 

47. Mercury combines with sulphur and phosphorus 
very readily. 

Exp. If two parts of sulphur by weight, and one of 
mercury, be triturated together in a mortar, the mercury 
gradually disappears and the mass assumes a black col- 
our. In this slate, it was formerly called ethiops mineral^ 
but it is now found to contain mercury, sulphur, and sal- 



2 io INTRODUCTION 

phuretted hydrogen, and on that account, is denominated 
kydro-sulpkurct of mercury. The sulphur imbibing hy- 
drogen from the moisture of the atmosphere. 

48. If hrdro-sulphuret of mercury be heated, part of 
the sulphur is dissipated, and the compound assumes a 
deep violet colour. 

49. Vermillion is composed of mercury and sulphur, 
united by fusion and sublimed. It is obtained in a tine 
red cake, and in this state it was called cinnabar ; it is 
the red sulphuret of mercury. 

50. Phosphuret of mercury is formed from phospho- 
rus and the black oxide of mercury, or protoxide, melted 
in a retort filled with hydrogen gas. This latter sub- 
stance prevents the combustion of the phosphorus. This 
substance being formed of the oxide and not of the pure 
mercury, has been called black phosphuretted oxide of 
mercury. 

51. The following metals are soluble in mercury, 
when mixed in sufficient quantities. Gold, lead, bis- 
muth, osmium, silver, tin r z*jc. 

52. On the amalgamating property of mercury, the 
silvering of looking glasses depends. An amalgam is form- 
ed, by pouring mercury on tin foil, laid perfectly smooth 
on a marble slab, and the glass slided on it, and kept 
down by weights. 

53. Sulphuric acid will not act upon mercury, when 
cold ; hence, it has been used to purify mercury from, 
foreign materials, for barometers and thermometers. 

54. Muriatic acid does n©t sensibly act on metallic 
mercury, except by long digestion, when it oxidates a 
part, which is immediately dissolved. It readily dissolves 
the oxides. 

55. Nitric acid acts with great energy on mercury, 
and during the operation, nitrous gas is disengaged. — - 



TO CHEMISTRY. 249- 

The nitrate contains a greater or less proportion of oxy- 
gen, as it is prepared with or without heat. 

56. All the nitrates of mercury are very caustic, and 
form a deep purple^ or black spot on the skin. They 
afford crystals, which differ according to the state of the 
solution. 

57. When the crystals of nitrate of mercury are sub- 
mitted to a long continued heat, they give out a portion 
of nitric acid, and are converted into a bright red oxide, 
called red precipitate. 

58. Mercury combines with chlorine, and forms two 
well known compounds, viz. calomel, or the proto chlo 
ride, and corrosive sublimate, or the perchloride, called, 
by some, the deutochloride. 

59. The perchloride of mercury consists of 

Mercury, 25 73.53 

Chlorine^ 9 26.67 





100.00 


The protochloride of 




Mercury, 25 


84.746 


Chlorine, 4.5 


15.254 



100.000 
60. Mercury is extensively used in the arts and i^ 
medicine. 

PRACTICAL QUESTIONS. 

What is platinum and its characteristics ? 

Is it easily fusible ? 

What is a test of platinum ? 

Does platinum combine with sulphur ? 

Can platinum be united with phosphorus ? 

What are the properties of phosphuret of platinum ? 

Does platinum unite with any of the metals ? 

What effect does it have on gold ? 



250 INTRODUCTION 

What on silver ? 

What on copper ? 

What are the oxides of platinum ? 

How is the peroxide obtained ? 

In how many proportions does it unite with chlorine I 

Wliat characters do the salts of platinum possess ? 

How is fulminating platinum prepared ? 

What are its properties ? 

What is gold, and what are its properties ? 

In what is it soluble ? 

What will precipitate it from its solution ? 

What is the theory of the solution of gold in nitre-mu- 
riatic acid ? 

How many oxides of gold are there ? 

Does gold combine with any other metals I 

What test have you for gold ? 

Has mercury any affinity for gold ? 

What are gold coins and medals ?' 

Illustrate this. 

What are the characteristics of silver ? 

W^hat is the phenomenon produced by electricity upon 
it? 

What effect has the air upon it ? 

What are the oxides of silver ? 

What does silver form with chlorine ? 

How do you form fulminating silver ? 

What are its properties ? 

Is there any other fulminating compound ? 

What is the cause of the detonation ? 

Is silver soluble in nitric and sulphuric acids ? 

How can nitrate of silver be decomposed ? 

How are Dial plates, scales of barometers, &c. silver 
ed? 

How do you form a useful solvent of silver t 



TO CHEMISTRV. 251 

How can Diana's tree be formed J 

Where is silver found ? 

What is palladium ? 

What are its characteristics ? 

is it soluble in the acids ? 

How is it precipitated ? 

What is mercury ? 

How is it distinguished ? 

How many oxides are there of this metal ? 

Does mercury combine with sulphur and phosphorus / 

What is the effect of heating hydro-sulphuret of mer- 
cury ? 

Of what is vermillion composed ? 

How is phosphuret of mercury formed ? 

What metals are soluble in mercury ? 

On what does the silvering of looking glasses depend ? 

Will sulphuric acid act upon mercury ? 

Will muriatic acid ? 

What is the action of nitric acid on mercury ? 

What property have the nitrates ? 

How is red precipitate formed ? 

Does mercury combine with chlorine ? 

What are the proportions in the protochloride and the 
perchloride ? 

Is mercury much used ? 



CHAP. XXVIL 

Of Copper — Iron — Tin—L&ad — Nickel — Cadmium — Zinc 
1. Copper is a metal of a peculiar reddish brown col- 
our, hard, ductile, malleable and sonorous, and of con- 
siderable tenacity. 



252 INTRODUCTION 

2. It melts in a heat about sufficient to melt gold, 
and exhibits a bluish green flame ; by a violent heat it 
boils, and is volatilized, partly in a metallic state. 

3. A wire one tenth of an inch in diameter will bear 
more than three cw r t. without breaking. 

4. Copper rusts on exposure to the air, but the cor- 
roded part is very thin, and preserves the metal below 
from farther corrosion. 

5. There are two oxides of copper. The protoxide 
is of a fine orange colour, and is obtained by digesting a 
solution of muriate of copper with copper filings in a 
close vessel. The colour passes from green to dark 
brown, and grey crystalline grains are deposited. The 
solution of these yields, by potash, the protoxide. It 
consists of 8 copper, and -{- 1 oxygen. 

6. The peroxide is of a black colour, and is procura- 
ble by heat, or by drying the hydrated oxide, precipitat- 
ed by potash from the nitrate. It consists of 8 copper 
-f- 2 oxygen. 

7. Copper combines with chlorine in two propor- 
tions, forming the protochloride and the perchloride.— = 
The protochloride consists of 

Chlorine, 36 or 1 prime = 4.45 35.8 
Copper, 64 1 prime = 8.C0 64.2 



100 12.45 100.0 
The perchloride consists of 

Chlorine, 53 or 2 primes = 8.9 52.7 

Copper, 47 1 prime = 8.0 47.3 



100 16.9 100.0 

8. It unites with iodine, forming insoluble substances 
of a dark brown colour, called iodides of copper. 



TO CHEMISTRY. £53 

9. When copper is exposed to a stream of oxygen 
and hydrogen gases, it takes fire and burns with great 
brilliancy, emitting a lively green light, of such intensity 
as to be scarcely endured by the eye. Copper leaves, 
or wire, may be burned by the galvanic fluid. 

10. Copper unites with sulphur and phosphorus.— 
"The sulphuret maybe formed readily, by mixing copper 

filings with sulphur, and making them into a paste with 
water. 

11. The phosphuret may be formed by fusing to- 
gether sixteen parts of copper, sixteen parts of phospho- 
ric glass, and one of charcoal. 

12. Copper unites with the metals and forms alloys, 
which are of considerable importance ; an alloy of cop- 
per and platinum takes a fine polish, and is not liable to 
rust ; on this account, it has been used in reflecting tele- 
scopes. 

13. Sulphuric acid, when concentrated and boiling, 
dissolves copper. If water be added to the solution, it 
assumes a blue colour, and on evaporation, produces 
crystals, called blue, or Roman vitriol, and by the present 
nomenclature, sulphate of copper. These are much more 
beautiful, if a little nitric acid be added to the solution. 

14. The nitric acid acts on copper with great ener- 
gy, and disengages a large quantity of nitrous gas. The 

solution, or evaporation affords crjstals of a green col- 
our, which are deliquescent. 

15. The acetic acid acts upon copper, and forms 
what is called verdigris, which is a crude acetate. This, 
when dissolved in vinegar and evaporated, forms beauti- 
ful gre^n crystals, which are subdeliquescent in the air. 

16. The following acids form insoluble salts with 
peroxide of copper, viz. Antimonic, antimonous, bora- 
cic, Chromic, molybdic, phosphoric and tungstic. The 



254 INTRODUCTION 

first two are green, the third is brown, the Fourth and 
fifth green, ai d the sixth is white. 

17. The oxides of copper are poisonous ; but sugar 
is said to be an antidote of undoubted efficacy. 

18. Copper, with about a fourth of its weight of lead, 
forms pot metal ; with the same proportion of zinc, it 
composes brass. Mixture of zinc and copper, in differ- 
ent proportions, form the various compounds of Dutch 
gold, Prince's metal, pinchbeck, &,c. Copper and tin, 
with a little zinc, form bell-metal, or gun-metal. When 
tin is nearly one third of the alloy, it takes a beautiful 
polish, and is called speculum metal, from its being used 
in the construction of reflecting telescopes. 

19. Iron is of a bluish white colour, of considerably 
hardness and elasticity ; very malleable and exceedingly 
tenacious and ductile ; very easily oxidized, and difficult 
of fusion ; on which account, it is brought into different 
shapes by hammering. It possesses a property which 
no other metal does, except platina ; that of being weldr 
ed, or united by forging, after being brought to a white 
heat. 

20. Iron cannot be hammered into leaves as thin as 
gold or silver, but it may be drawn into a wire as fine as 
a human hair; a wire one tenth of an inch in diameter, 
will sustain without breaking, nearly six cwt. 

21. When iron is exposed to the action of moist air, 
it acquires weight by gradually attracting oxygen, and 
hydrogen gas escapes ; , a yellow rust forms on the sur- 
face, which is not a simple oxide, as it contains a por- 
tion of carbonic acid. 

22. Concentrated sulphuric acid scarcely acts upon 
iron, unless when boiling. If the acid be diluted with 
two or three parts of water, it dissolves iron readily. 



TO CHEMISTRY. 2oo 

without the assistance of heat. During' the solution, hy- 
drogen gas escapes in large quantities. 

23. Green sulphate of iron is much more soluble in 
hot than cold water, and therefore crystallizes by cooling, 
as well as by evaporation. 

24. The crystals are efflorescent, and fall into a white 
powder b}^ exposure to a dry air ; the iron becoming 
more oxidized than before. 

25. A solution of sulphate of iron exposed to the air, 
acquires oxygen, and the metal being peroxidized, falls 
to the bottom. 

26. Sulphate of iron is decomposed by alkalies and 
by lime. Caustic fixed alkali precipitates the iron in 
deep green flocks, which are dissolved hy the addition 
of more alkali, and form a red tincture. 

27. Vegetable astringent matters, such as nut-galls, 
the husks of nuts, logwood, hyson and souchong tea, &c. 
which contain tannin and gallic acid, precipitate a fine 
black fecula from sulphate of iron, which remains sus- 
pended for a considerable time in the fluid, by the addi- 
tion of gum arabic. This fluid is well known by the 
name of ink* 

28. The beautiful pigment, well known in the arts 
by the name of prussian blue, is likewise a precipitate, 
afforded by the sulphate of iron and prussine, or cyano- 
gen. 

29. Iron is soluble in nitric and muriatic acids. The 
former does not afford crystals on evaporation, but de- 
posits- the oxide of a red colour. 

30. Iron combines with sulphur, phosphorus and car- 
bon, forming sulphurets, phosphurets and carburets of 
iron. 

Exp. If equal quantities of iron filings and sulphur 
ase formed with water into a paste, the sulphur decern- 



256 INTRODUCTION 

poses the water, and absorbs the oxygen so rapidly, that 
this mixture sometimes takes fire, although buried under 
ground: This fact is supposed to afford an explanation 
of the origin of volcanoes* 

Exp. 2. The phosphuret of iron may be formed by 
dropping small bits of phosphorus into iron filings heat- 
ed red hot. 

31. The carburet of iron is found native, known un- 
der the name of plumbago, or black lead. It consists of 
about one tenth iron, the rest is carbon. 

32. Cast iron is the name given to the metal when 
first extracted from the ores ; by heat and hammering, 
it is formed into what is called wrought iron. Steel is a 
compound of iron and carbon. 

33. Iron may be distinguished from steel, by exhibit- 
ing a whitish grey spot with nitric acid, whereas the 
steel becomes black, from the carbon which it contains. 

34. The yellow spots, called iron moulds, which are 
frequently occasioned on cloth by washing ink spots with 
soap, may, in general, be removed by lemoa juice, or 
the oxalic, or nitric acid, or by muriatic acid diluted 
with live or six parts of water ; but in this case, the 
cloth should be immediately washed. 

35. There are two oxides of iron, the protoxide, 
which is black. Its composition seems to.be 

Iron, 100 77.82 3.5 

Oxygen, 28.5 22.18 1.0 



100.00 4.5 

The peroxide, which is red, it seems to be a com- 
pound of 

Iron, 100 70 = 4 primes. 

Qxygen^ 43 30 = 3 primes 



TO CHEMIST&Y. 257 

36. Iron is found in abundance in almost every part 
of the world, and is the most useful of all minerals. 

37. Tin is a metal of a yellowish white colour, con- 
siderably harder than lead, scarcely sonorous, very mal- 
leable, though not very tenacious. Under the hammer 
it is extended into leaves called tin foil, which are about 
__i__ of an inch in thickness, and might easily be beaten 
to less than half that thickness. 

38. It is melted at a temperature about double that 
of boiling water, or 430° F. 

39. When exposed to the air it loses its lustre, and 
assumes a greyish white colour ; but when melted in an 
open vessel, its surface verj' soon becomes covered with 
a grey powder, which is the oxide of tin. If the heat 
be continued, the powder becomes yellow. 

40. There are two oxides of tin, the protoxide, which 
is grey, and the peroxide is white. 

41. The protoxide consists of 13.5 per cent of oxy- 
gen. 

The peroxide is composed of 

Tin, 100 

Oxygen -f 27.2 
And if w r e regard it as containing 2 primes of the lat- 
ter principle to 1 of metal r the prime of this will be 
7.353. The mean may be taken at 7.35. 

42. Tin unites with chlorine in two proportions, 
forcing the protochioride and perchloride of tin. 

43. Sulphur unites with tin in two proportions. One 
may be made by fusing tin and sulphur together. It is - 
of a blue colour and lamellated texture. It consists of 
7.35 tin and -f- 2 sulphur. The bisulphuret is made by 
heating together peroxide of tin and sulphur. It is of a 
beautiful gold colour, and appears in fine flakes. It was < 



253 INTRODUCTION 

forme rly called aurum musivum, or Mosaic gold. It con- 
sists, according to Dr. J. Bavy, of 

7.3 tin, or 1 prime tin. 

4.00 sulphur, 2 primes sulphur. 

44. Tin combines with various metals and forms al- 
loys; with mercury it forms an amalgam, which is used 
for electrical purposes, and silvering of mirrors. 

45. The alloys of tin are used in the manufacturing 
of cannon, bells, and various articles made of bronze, and 
for reflecting telescopes. 

48. Tin plates are made by dipping plates of iron, 
properly scoured, into melted tin. 

47. Common pins are whitened, by boiling them with 
tin for five or six hours in water, acidulated with tartaric 
acid. Brass being a compound of zinc and copper, the 
zinc has an affinity for the tin, and in this case, forms 
the union. 

48. Tin is soluble in all the mineral acids, and forms 
sulphates, nitrates, muriates, &c. 

49. When nitric acid is used as a solvent, it is decom- 
posed by the tin, and red fumes are thrown oif with ra- 
pidity. 

Exp. Add to the nitric solution, a solution of potash. 
The tin decomposes both the acid and the water, the ni- 
trogen of the former combines with the hydrogen of the 
latter and forms ammonia,, which is evolved in the form 
of gas. 

50. Tin decomposes the muriate of ammonia. 

Exp. Put equal part9 of granulated tin and muriate 
of ammonia into a retort, which is to be adopted to a re- 
ceiver, in a mercurial apparatus ; as soon as heat is ap- 
plied to the retort, a decomposition takes place ; the 
ammonia is disengaged in the form of gas, the muriatic 



TO CHEMISTRY. 259 

acid combines with the tin, forming a solid muriate of 
tin, which may be decomposed with water. 

51. The muriate of tin is employed in the process of 
dyeing ; it is the basis of the scarlet dye. In glazing, 
and in the forming of Plumber's solder, tin is used. 

52.. Lead is a bluish white metal, very soft and flexi- 
ble,, not very tenacious, and consequently incapable of 
being drawn into fine wire, but is easily extended into 
thin plates under the hammer. In a strong heat it boils 
and emits fumes, during which time, its oxidation pro- 
ceeds- with considerable rapidity, if exposed to the air c 
It congeals in a crystalline form. It is not much altered 
on exposure to the air, though the brightness of.itssur-. 
face soon tarnishes. 

53. There are two, if not three combinations of lead 
with oxygen, i. The pow r der precipitated from the ni- 
trate with potash, forms the yellow protoxide. When 
somewhat vitrified, it constitutes litharge, and combined 
with carbonic acid, white lead. 2. When massicot has 
been exposed for about 48 hours to the flame of a rever- 
berating furnace, it becomes red lead, or minium. This 
substance has a specific gravity of 8.94. At a red heat, 
it gives out oxygen and passes to the protoxide. It con- 
sist of 100 lead + 11.08 oxygen. 3. If upon 100 of red 
lead, we digest nitric acid of specific gravity 1 .26, 92.5 
parts will be dissolved. But 7.5 of a dark brown pow- 
der, will remain insoluble. This is the peroxide of lead, 
and consist of 100 lead, and -{- 15.4 oxygen. 

54. Lead combines with chlorine and iodine ; with 
the former^ it forms a greyish white powder; with the 
latter, a fine yellow. 

55. The salts of lead have the protoxide for their 
base. 



£60 INTRODUCTION 

56. Most of the acids attack lead ; but the sulphuric 
requires a boiling heat for the purpose. Nitric acid at- 
tacks lead with violence. Muriatic acid acts directly on 
lead by heat, oxidizing it, and dissolving part of its ox- 
ide. 

57. The acetic acid dissolves lead and its oxides ; 
when evaporated^ the solution affords needle formed' 
crystals, called sugar of lead, from its sweet taste. 

58. The common sugar of lead is an acetate ; and 
GoulanFs extract, made by boiling litharge in vinegar, a 
subacetate. The acetate crystallizes in needles, the sub- 
acetate in plates. 

Exp. Dissolve one part of sugar of lead in forty parts 
of water, in a phial, suspend in it a little ball of zinc, and 
leave it undisturbed. The zinc will soon be covered 
with a moss like substance, which increases gradually, 
shooting out into a sort of leaves, resembling in some 
measure, the form of a tree. The phenomenon of this 
depends on galvanism. 

59. Oils dissolve the oxide of. lead, and become 
thick and consistent, in which state, they are used as the 
basis of plasters, cements, for waterworks, &c. 

60. Sulphur readily dissolves lead in the dry way, 
and produces a brittle compound, of a deep grey colour 
and brilliant appearance. 

61. The phosphoric acid exposed to heat, together 
with charcoal and lead, becomes converted into phospho- 
rus, which combines with the metal; This combination 
does not differ much from ordinary lead; it is malleable,, 
and easily cut with a knife ; but is more easily tarnish- 
ed, when exposed to the air. 

62. Oxide of lead decomposes muriate of soda, and is 
formed into a pigment called Patent yellow. 



TO CHEMISTRY. 261 

Exp. Mix two parts of finely powdered red lead, with 
one of common salt, and form the whole into a paste 
with water, the alkali will be disengaged and the acid 
will unite with the oxide of lead. If the alkali be wash- 
ed off, and the mass dried and fused in a crucible, a hard 
heavy yellow substance will be formed. 

63. Lead unites with most of the metals and forms 
alloys. 

64. Lead is generally found in veins of rocks, com. 
bined with silver, antimony, sulphur, bismuth,&,c. When 
combined with sulphur, it is called galena,.. 

65. Nickel is a metal extremely hard, of a uniform 
texture, and of a colour between silver and tin, very difl 
ficult to be purified, it is magnetical. It even acquires 
polarity. It is malleable both cold and red hot, and is- 
scarcely more fusible than manganese. 

66. There are two oxides of nickel, the dark asfi 
grey, and the black. The protoxide is a compound of 
100 metal and 28 oxygen. The prime equivalent of the 
metal will be 3.6. That of the protoxide 4.6. 

67. The salts of nickel have usually a green colour 
and yield a white precipitate with ferro-prussiate of 
potash. Ammonia dissolves the oxide of nickel. Sul- 
phuretted hydrogen and infusion of galls occasion a pre- 
cipitate. Their composition has been very imperfectly 
ascertained. 

68. Nickel is soluble in the nitric and nitro-muriatic 
acids. The nitric solution has a dark green colour, and 
carbonate of potash throws down a green precipitate, 
which assumes a dark grey colour when heated 

69. Nickel combines with gold, copper, iron, tin and 
leadi Its oxide gives a beautiful dark green colour to 
porcelain. 



262 INTRODUCTION 

70. Cadmium is a new metal discovered by Mr. 
Stromger, in 1817, in some carbonate of zinc which he 
was examining, in Hanover. 

71 It is a fine white metal with a slight bluish grey^ 
approaching to that of tin, which metal it resembles in 
lustre and susceptibility of polish. Its texture is com- 
pact and its fracture hackly. It crystallizes on cooling, 
and presents on its surface the appearance of leaves of 
fern. It is flexible and yields readily to the knife. It is 
harder and more tenacious than tin, and stains paper and 
the fingers. It is ductile and malleable, but when long 
hammered flies off in scales. It melts and is volatilized 
at a red heat. Its vapour may be condensed in drops 
like mercury, and exhibits traces of crystallization. 

72. There is but one oxide of Cadmium, which con- 
siststs of 100 of metal combined with 14.352 of oxy- 
gen. 

73* It is soluble in liquid ammonia and the acids. 

74. Cadmium unites easily with most of the metals 
and forms alloj^s ; which are brittle and colourless. 

75. Zinc is a metal of a bluish white colour, some- 
what brighter than lead, of considerable hardness and so 
malleable as not to be easily broken by the hammer. It 
is very easily extended by the rollers of the flatting mill- 
When broken by bending, it* texture appears as though 
composed of cubical grains. It melts at about 700° F* 
and soon after it becomes red hot, it burns with a dazzling 
white flame of a bluish yellow tinge, and is oxidized with 
such rapidity that it flies up in the form of white flowers 
called Jlowers of zinc. 

76. There is but one oxide of zinc which consists of 
100 metal-J-2.4i oxygen. The prime equivalent appears 
to be 4.1. 



TO CHEMtSTRY* ^63 

77. Zinc combines with chlorine and forms a substance 
of a whitish ^rey colour, and semi-transparent. 

78. Most of the acids dissolve z,nc and form salts; 
sulphate of zinc or white vitriol is much used in the 
arts. 

79. Zinc will decompose nitric acid. 

Exp. Put some granulated zinc in a Florence flask, 
and pour over it weak nitric acid ; a strong* effervescence 
ensues, and nitrous gas is disengaged. 

80. Zinc is obtained from Lapis Calmninaris and other 
minerals. 

81. It is used in making brass, in forming amalgams 
for electrical purposes, &c. Zinc filings are mixed with 
gunpowder, to produce the brilliant stars in artificial fire- 
works. 

PRACTICAL QUESTIONS* 

What is Copper ? 

What heat is required to melt and cause it to 
boil? 

How much will a wire 1 10th of an inch in diameter 
bear? 

What effect does the air have on copper ? 

What are the oxides of copper ? 

What is the pertoxide ? 

How many chlorides are there ? 

What is the iodide ? 

What is the effect when copper is exposed to a stream 
of oxygen and hydrogen gases ? 

Does copper unite with sulphur ? 

How do you form the phosphuret ? 

Does copper unite with the metals ? 

Does sulphuric acid dissolve copper? 

What effect has nitric acid on copper? 



$64 *NTR0DUCTI0N 

What is the action of acetic acid on copper 7 

What acids form insoluble salts with peroxide of cop- 
per? 

Are the oxides of copper poisonous ? 

What are the different alloys of copper ? 

What is iron ? 

What is the ductility of iron ? 

What is the effect of moist air on iron ? 

Does concentrated sulphuric acid act upon iron ? 

What is the solubility of green sulphate of iron ? 

What effect does air have on sulphate of iron ? 

How is sulphate of iron decomposed ? 

What effect has vegetable astringents on iron ? 

What is Prussian blue ? 

Is iron soluble in nitric and muriatic acids ? 

Does iron combine with sulphur, phosphorus and car- 
bon? 

What is Plumbago ? 

What is Cast iron ? 

How do you distinguish iron from steel ? 

How can iron mould be removed from cloth •? 

How many oxides of iron are there ? 

What are their compositions ? 

Where is iron found ? 

What is tin ? 

What heat is required* to melt it? 

What effect does the air and heat have upon it^ 

How many oxides are there ? 

What are their proportions ? 

How many combinations has tin with chlorine ? 

How many proportions with sulphur ? 

Is tin alloyed with any of the meials ? 

For what are the alloys used? 

How are tin plates made ? 



TO CHEMrSfRY. 265 

How are pins whitened ? 
Is tin soluble in the mineral acids ? 
What effect has tin on the nitric acid ? 
Does tin decompose ammonia? 
Illustrate it. 

What use is the muriate of tin ? 
What is lead? 

How many oxides of lead are there ? 
Does lead combine with chlorine and iodine ? 
What have the salts of lead for their base ? 
Have the acids any effect on lead-? 
What is sugar of lead ? 

How is a lead tree formed, and what is the 
cause ? 

What effect have oils on the oxides of lead ? 
What effect has sulphur on lead ? 
What effect has the phosphoric acid ? 
What is Patent yellow ? 
Does lead unite with the other metals ? 
Where is lead found ? 
What is Nickel ? 

How many oxides of nickel are there? 
What do the salts of nickel exhibit? 
In what acids is nickel soluble ? 
With what does nickel combine? 
What is Cadmium ? 
What are its properties? 
How many oxides are there ? 
in what is it soluble ? 
Does it unite with the metals ? 
What is zinc ? 

What are the oxides of zinc? 
Does zinc Combine with chlorine ? 
23 



266 INTRODUCTION 

Do the acids dissolve zinc ? 
from what is zinc obtained ? 
For what is it used ? 



CHAP. XXVIII. 

Of Bismuth — Antimony — Manganese — Cob a lt~ Tellurium, 

1. Bismuth is a metal of yellowish, or reddish white 
colour, little subject to change in the air. It is somewhat 
harder than lead, and is not malleable. Its fracture ex- 
hibits large shining plates, disposed in a variety of posi- 
tions ; thin pieces are sonorous. It melts at a tempera- 
ture of 480° F. and its surface becomes of a greenish 
grey or brown oxide. A stronger heat ignites it, and 
causes it to burn with a small blue flame, at the same 
time a yellowish oxide known by the name of Jiowers of 
bismuth is sublimed. This oxide appears to rise in conse- 
quence of the combustion, for it is very fixed, and runs 
into a greenish glass when exposed to heat alone. 

2. This oxide consists of 100 metal-fl 1.275 oxygen, 
Its prime equivalent will be 9.87, and that of the metal 
itself, 8.87. The specific gravity of the metal 9.85. 

3. The sulphuric acid has a slight action on bismuth, 
when it is concentrated and boiling. Sulphurous acid gas 
is evolved, and part of the bismuth is converted into a 
white oxide. A small portion combines with the sulphur- 
ic acid and forms a deliquescentsah in the form of small 
needles. 

4. The nitric acid, dissolves bismuth with the great- 
est rapidity and violence ; at the same time, much heat 



TO CHEMISTRY. *& 

is- extricated, and a large quantity of nitrous oxide is dis- 
engaged. The solution when saturated, affords crystals 
as it cools. The salt detonates weakly and leaves a 
yellow oxide behind, which deliquesces in the air. 

Exp. When the nitric solution is diluted with pure 
water, the metal falls down in the form of a white oxide 
called, formerly, Magestery of bismuth This affords a test 
by which bismuth is distinguished from the other me- 
tals. 

5. The muriatic acid, does not readily act upon bis- 
muth. 

6. Chlorine acts so violently on bismuth as to cause 
it to take fire. The substance formed is chloride of bis- 
muth, formerly called butter of bismuth. 

7. Iodine combines with bismuth and forms- an iodide 
of an orange yellow colour. 

8. Sulphur combines with bismuth in two proportions^ 
forming sulphurets. 

9. Bismuth combines with most metals and renders 
the,m--more brittle. 

|0. Bismuth is used in the formation of printers' small 
types, and to make pewter. It forms the bases of a sym- 
pathetic ink. In this experiment the acetic acid must 
be employed for the solution of the metal. Characters 
written with this solution become visible,when exposed to 
sulphuretted hydrogen,, 

11. The term Antimony is used to denote in com*- 
merce a metallic ore consisting of sulphur combined with 
the metal. It consists of about 26 per cent of anti- 
mony. 

12. Antimony when pure, is of a dusky white colour, 
very brittle, and of a plated or scaly appearance, the 
plates crossing each other in every direction. 

13. It may be obtained in the form of a metal from 



263 JxTTRODUCTION 

the sulphuret, by fusing three parts in a covered crucible* 
with one of iron filings; or by fusing it with animal char- 
coal. 

The product was formerly called regulus of Anti-. 
mony. 

15. It requires for its complete fusion a heat near- 
ly 450° F. 

15. There are three if not four combinations of an- 
timony with oxygen. 

In 100 partsi 
The protoxide consists of 

11 metal +1 oxy. or 91f + 8x 
Deutoxide 11 +2 84.6 + 15.4 

Tritoxide 11 +3 78.6 + 21.4 

Peroxide 11 +4 73.4+36.6 

16. Antimony looses its lustre in the air ; but it is not 
altered by being kept under water. When steam is made 
to pass over red hot antimony, it is decomposed so rapid- 
ly that a violent detonation ensues. 

17. When the native sulphuret is slowly roasted, it 
gradually loses its sulphur, the metal attracts oxygen, 
and is converted into a grey oxide, this being fused by a 
strong heat, runs into a glassy substance and is called the 
glass of antimony. 

18. If the native sulphuret be reduced to powder and 
boiled with pure potash, the solution deposits on cooling 
an hydro-sulphuret, formerly called kermes mineral. A 
similar compound with a larger proportion of sulphur was 
formerly called golden sulphur of antimony. 

19. Antimony combines with other metals and forms 
alloys ; between six and seven parts of lead and one of 
antimony form an , alloy of which printer's types are 
made. Sometimes^ however, a less quantity of antimony 
is used, 



TO CHEMISTRY. 2G9 

20. Antimony combines with the acids and forms salts 
which have been much used in medicine, especially that 
of tartaric acid and antimony called tartar e.ne^'c, (tar- 
trate of antimony.) The white deutoside of antimony is 
the bases of this salt. 

21. The empirical medicine called James* powder 
is a compound of which antimony is the principal ingre- 
dient. 

22. Antimony is obtained from an ore which is abund-; 
ant in some parts of the world, prrticularly in Germany 
and Norway^ 

23. Manganese is a metal of a dull whitish colour 
when broken, but which soon grows dark by oxidation 
from the action of the air. 

24. It is hard, brittle, though not pulverizwle, and 
rough in its fracture; It is so difficultly fusible, that no 
heat, hitherto exhibited, has caused it to run into masses 
of any considerable magnitude. When broken into pie- 
ces it falls into powder by spontaneous oxidation. 

25. Manganese heated in oxygen or chlorine, takes 
fire and forms an oxide or chloride. 

26. Chemists differ with- regard to the number of 
combinations with oxygen; Sir H. Davy has two, M. 
Thenard, four, Mr. Brande, three, and Berzelius, five. 
The black oxide is xhe state in which it us usually 
found. 

27. Manganese is soluble in the acids, but most readi- 
ly in the nitric It > is precipitated by alkalies in the 
form of white powder. It combines with the other me- 
tals and is scarcely ever found, but w hen mixed, more or 
less, with iron. 

£8. When powdered manganese and nitrate of potash 
are mixed together and thrown into a red hot crucible, 
23* 



270 INTRODUCTION 

the nitrate is decomposed, and a highly oxidized manga- 
nese with potash is obtained, which has the following 
properties. It exhibits different colours,according to the 
quantity of water that is added to it. A small quantity 
gives a green solution, a little more changes it to blue . 
some more gives it a purple. The experiment may be 
varied by putting equal quantities of this substance into 
two glass vessels, and pouring on the one hot, and on the 
other cold water, the same material with water of differ 
ent temperatures assumes various shades of colours, and 
on that account it has been called the chameleon mineral. 

29. Manganese in a state of oxide has been found in 
different parts of the World. It is very abundant in some 
parts of the United States, and is of an excellent quality. 
It is us«d in bleaching and in the manufacture of 
glass. 

30. Cobalt is a brittle, somewhat soft but difficultly 
fusible metal, of a reddish grey colour, of little lustre. 
It melts at 130° Wedg. 

31^ Cobalt is susceptible of magnetism, but in a lower 
degree than that of nickel. 

32. Oxygen combines with cobalt in two proportions, 
forming a dark blue protoxide, and a black perox- 
ide. 

The first dissolves in acids without effervescence. 
It consists of cobalt, 5.4 100 84.38 
oxygen, 1.0 18.5 15.62 



100.00 



The peroxide, cobalt, 5.4 100 73 
oxygen, 2.0 37 27 

100 



TO CHEMISTRY. 271 

33. When cobalt is heated in chlorine it takes fire and 
forms the chloride. 

34. The best solvents of this metal are the nitric 
and nitro-muriatic acids. From these solutions sympa- 
thetic inks are formed. 

Exp. Digest one part of cobalt in a sand heat for 
some hours, with four parts of nitric acid, to the solution 
one part of the muriate of soda is to be added, and four 
parts of water. Write with this solution, when cold they 
will be illegible ; but on applying a gentle heat they as- 
sume a beautiful blue or green colour. 

35. Cobalt combines in small proportions with most 
of the acids, also with ammonia, phosphorus and most of 
the metals. It is found mineralized with arsenic. 

36. Cobalt is found in England, Germany and the 
United States. 

37. Tellurium is a metal found in the state of an ore 
in Transylvania. 

38. Pure tellurium is of a tin white colour, verging 
to lead grey, with a high metallic lustre ; of a foliated 
fracture, very brittle, so as to be easily pulverized. It 
melts before ignition, at a temperature nearly that at 
which lead fuses. It burns on charcoal, before the blow 
pipe, with a vivid blue flame, greenish on the edges, 
and is dissipated in greyish white vapours, of a pungent 
smell which condense into a white oxide. 

39. Tellurium is oxidized and dissolved by the prin- 
cipal acids. 

40. It unites with sulphur, and forms a lead coloured 
striated sulphuret 

41. Tellurium and hydrogen combine to form a gas, 
called telluretted hydrogen. It may be formed in the fol- 
lowing manner. Hydrate of potash and oxide of telluri- 
um are ignited, together with charcoal, and the mixture 



-IZlt ItfTRODUCTIQS 

acted upon by diluted sulphuric acid, in a retort connect- 
ed with a mercurial pneumatic apparatus ; an elastic 
fluid is generated, consisting of hydrogen holding tellu- 
rium in solution. The telluretted hydrogen is soluble 
in water and forms a claret coloured solution. It com- 
bines with the alkalies. It burns with a bluish flame, 
depositing oxide of tellurium. Its smell is very strong 
and peculiar, resembling in some measure, sulphuretted 
hydrogen. Its specific gravity is 2.2916. 

PRACTICAL QUESTIONS. 
What is bismuth, and its properties ? 
What is the proportion of oxygen in bismuth ? 
Does the sulphuric acid act on bismuth ? 
What action has the nitric acid ? 
Does the muriatic acid act upon it ? 
What is the action of chlorine ? 
Of iodine ? 

Does sulphur combine with bismuth ? 
Does bismuth combine with any of the metals ? 
What is the use of bismuth ? 
What is antimony ? 
What are its properties? 
How can it be obtoined from the sulphuret ? 
What heat does it require for its fusion, and how many 
combinations has it with oxygen ? 

Does the air have any effect upon it ? 

What is the glass of antimony ? 

What is Kertnes^ Mineral ? 

Does antimony combine with any other metal ? 

Does autimony combine .with acids ? 

What is James's powder ? 

From what is antimony obtained ? 

What is manganese ? 



TO CHEMISTRV. 273* 

What are its characteristics ? 

What is the effect of heating manganese in oxygen or 
chlorine ? 

What are the number of combinations with oxygen ? 

Is manganese soluble in the acids ? 

How is the chameleon mineral formed ? 

Where is manganese found ? 

What is cobalt ? 

Is it susceptible of magnetism ? 

How many combinations of oxygen are there ? 

What is the effect of heating cobalt in chlorine ? 

What are the solvents of this metal? 

How is a sympathetic ink prepared with cobalt ? 

Does cobalt combine with the acids and alkalies ? 

Where is cobalt found ? 

What is tellurium ? 

What are its characteristics ? 

How is tellurium oxidized and dissolved ? 

Does it combine with sulphur ? 

What is the combination of tellurium and hydrogen,? 



CHAP. XXIX. 

Of Arsenic — Chromium — Molybdenum — Tungsten— *-Coltm- 
bium — Selenium — Osmium* 
1. Arsenic is a metal of a bluish white colour, subject 
to tarnish, and grow first yellowish, then black, by expo- 
sure to the air. It is brittle, and when broken exhibits 
a lamellated texture. In close vessels it sublimes entire 
at 356° F. but burns with a small flame in contact with 
oxygen, 



£74 INTRODUCTION 

% What is called arsenic in the shops is a white ox- 
ide of arsenic. 

3. Arsenic is among" the most combustible of the 
metals; it burns with a bluish flame, exhales the smell 
of garlic, and sublimes in the state of arsenious acid. 

4. Concentrated sulphuric acid does not attack arse- 
nic when cold ; but if it be boiled upon this metal, sul- 
phurous acid gas is emitted, a small quantity of sulphur 
sublimes, and the metal is- reduced to an oxide. 

5. Nitrous acid readily attacks arsenic, and converts 
it into arsenious acid, or if it be employed in considera- 
ble quantities into arsenic acid. 

6. Boiling muriatic acid dissolves arsenic, but affects,; 
it very little when cold. This solution affords precipi- 
tates on the addition of alkalies. The muriatic solution 
when condensed in a close vessel and sublimed, forms 
butter of ar&emc. Thrown in powder; into chlorine, it 
burns with a bright white flame, and is converted into a. 
chloride. 

7. None of the earths or alkalies act upon it unless 
it be boiled a long time, in a fine powder, in a large pro- 
portion of an alkaline solution., 

8. Arsenic readily combines with sulphur by fusion 
and sublimation, and forms a yellow compound, called 
orpiment, or a red, called realgar.. 

9.^ Arsenic is soluble in fat oils in a boiling heat It 
unites with metals, and forms alloys. 

10. Iodine and arsenic unite, and form an iodide of a 
dark purple red colour, possessing the properties of an 
acid. It is. soluble in water, and its solution forms a solu- 
ble compound with potash. 

11. A mixture of oxymuriate of potash and arsenic 
forms a compound, which takes fire with great rapidity 



TO CHEMISTKY. 215 

Exp, Mix the oxy muriate and oxide of arsenic by 
stirring them together on paper, with the point of a 
knife. If two trains be laid on the table, one of gun- 
powder, the other of this mixture, and then brought in 
contact with each other at one end, so that they may be 
fired at once, the arsenical mixture burns with the ra- 
pidity of lightning, while the gunpowder comparatively 
slow. 

12. Arsenic destroys the magnetic property of iron 
and nickel. 

13. Arsenic in its metallic state enters into the con> 
position of several alloys for the formation of specula.-^- 
It is used in making small shot, to render the lead 
more capable oi' running into grains. It is employ- 
ed like many other metals, in dyeing and calico printing ; 
it enters into composition of some sorts of glass, and it 
forms several excellent pigments. 

14. Arsenic is a most deadly poison, the best antidote 
for which, is the sulphuret of potash. 

15. Chromium is a metal extracted either from the 
native chromate of lead, of iron. The latter being 
most abundant, is generally used. 

16. It is a porous mass of agglutinated grains. It is 
"very brittle, and of a greyish white, intermediate be- 
tween tin and steel. It is sometimes obtained in needle 
formed crystals, which cross each other in all directions,, 
It is susceptible of a feeble magnetism. It resists all 
the acids except the nitro-muriatic, which, at a boiling 
heat, oxidizes it and forms a muriate. 

17. Chromium is capable of combining with three 
portions of oxygen. 

18. The protoxide is green, infusible, undecompound- 
ed by heat, reducible by voltaic electricity, and not act* 
ed upon by the air* 



276 INTRODUCTION 

19. The deutoxide is a brilliant brown powder, itiso 
luble in acids, and scarcely soluble in alkalies. Muriatic 
acid digested on it, exhales chlorine. 

20. The peroxide is the chromic acid. 

21. The chromic acid is found combined with iron 
in considerable quantity, near Baltimore ; from this, the 
beautiful pigment, called chromic yellow is prepared. 

22. Molybdenum is a metal which has not yet been 
reduced into masses of any magnitude ; but has only 
been obtained in small separate globules, in a blackish 
brilliant mass. 

23. The globules are grey, brittle, and extremely 
infusible. By heat it is converted into a white oxide, 
which rises in brilliant needle formed flowers, like those 
of antimony. Nitric acid readily oxidizes and acidifies 
the metal. Nitre detonates with it, and the remaining 
alkali combin€s with its oxide. 

24. Molybdenum unites with several of the metals, 
and forms brittle or friable alloys. No acid acts upon 
it but the nitric and nitro muriatic ; but several acids 
act on its oxide, and afford blue solutions. 

25. When molybdate of ammonia is ignited in a cru- 
cible with charcoal powder, it is converted into the pro- 
toxide of the metal, of a brown colour, crystallized ap- 
pearance. The deutoxide is the molybdous acid, and 
the tritoxide the molybdic acid. 

Exp. A small rod of zinc or pure tin is acted upon by 
a solution of the acid, which becomes blue in consequence 
wt the loss of a portion of the oxygen. 

26. Tungsten is a metal obtained from a mineral 
Found in Sweden ; in its metallic state, it is somewhat 
like iron, and is rather brilliant. It is one of the hard* 
est of all metals, and the heaviest, except gold and plati 
num. It requires a very high temperature for its fusion. 



TO CHEMISTRY. • 21 i 

It is not acted upon by the magnet. When heated in an 
open vessel, it absorbs oxygen from the atmosphere, and 
is converted into an oxide. 

27. There are two oxides of tungsten, the brown and 
the yellow, or tungstic acid. 

28. The brown or protoxide has a rlea brown col- 
our, and when heated in the air, it takes fire and burns 
like tinder, passing into tungstic acid. The protoxide 
consists of 

Tungsten, 400 

Oxygen, 46.6 

29. When heated with chlorine, tungsten -burns with 
a deep Ted light, and forms an orange coloured volatile 
substance, which, when decomposed with water, forms 
the yellow oxide and muriatic acid. 

30. Columbium is a metal first discovered in a miner- 
al found in the British Museum, said to have been sent 
from Massachusetts, with some ores of iron. The min- 
eral is said to be a columbiate of iron, that is, to consist 
of one part oxide of iron, and three parts of a white col- 
oured substance, which possesses the properties of an 
acid, called columbic acid. 

31. It is procured from the oxide in the form of me- 
tallic grains, which are so hard as to scratch glass, and 
-are easily pulverized. Neither, nitric, muriatic, nor ni- 
tro muriatic acids have any action upon it, though di- 
gested oh it for several days. It has been alloyed with 
iron and timg-sten. 

32. Columbium is known to be the same as the metal 
found in yttro iantalite, a mineral of Sweden, and former- 
ly called tantalium* 

33. Selenium is an elementary body, extracted by M. 
Berzelius from the pyrites of Fahlun, which, from its 
chemical properties, he places between sulphur and tel- 

24 



278 INTRODUCTION 

lurium, though it has more properties in common with 
the former than the latter substance. 

34. When selenium, after being 1 fused, becomes solid, 
its surface assumes a metallic brilliancy of a verj r deep 
brown colour. Its fracture is conchoidal, vitreous, of 
the colour of lead, and perfectly metallic. Its powder 
has a deep red colour, but it sticks together readily when 
pounded, and then assumes a grey colour and smooth 
surface, like antimony and bismuth. In very thin pieces 
it is transparent, with a ruby red colour. Whea treated, 
it softens ; and at 212° it is semi-liquid, and melts com- 
pletely at a temperature a few degrees higher. During 
its cooling it retains for a long time a soft state. In this 
state it may be kneaded between the fingers and drawn 
out into long threads, which have considerable transpar- 
ency ; if viewed by transmitted light, they arc red ; but 
by reflected light, they are grey, and have the metallic 
lustre. 

35. Selenium is not a good conductor of caloric. It 
is also a non-conductor of electricity. 

3G. Its affinity for oxygen is feeble, when heated in 
the air, without coming in contact with a burning body, 
it is volatilized with a strong smell of horse radish. The 
odorous substance is a gaseous oxide of selenium. 

37. By heat in a large flask, filled with oxygen, sele- 
nium combines with the oxygen, and forms a substance 
which possesses the property cf reddening litmus paper. 
called selenic acid. 

38. Sulphur, phosphorus, the earths, and the metals^ 
combine with selenium, forming seleninrets. 

39. Osmium is a metal discovered in the ore of pla- 
tina, which has a peculiar and. pungent odour, resembling 
that of chlorine gas, whence it had its name. 



TO CHEMISTRY. 27Q 

40. It is of a" dark grey or blue colour, of some me- 
tallic lustre, infusible when excluded from the air, but 
easily oxidized, when heated in contact with it. It is 
not soluble in any of the acids: Its oxide forms a yellow 
solution with potash. 

4-1. The pure metal forms with gold and silver mal- 
leable alloys. 

42. The best test for the oxide of osmium is an infu- 
sion of galls, which soon becomes of a purple colour, an4 
afterwards changes to a vivid blue. 

PRACTICAL QUESTIONS. 

What is arsenic ? 

Is this the arsenic of the shops ? 

Does sulphuric acid act on arsenic ? 

What effect has the nitrous acid ? 

What effect has muriatic acid ? 

Do the earths and alkalies act upon it ? 

Does it combine with sulphur ? 

Does it unite with the oils and metals ? 

Does it unite with iodine ? 

What is the effect of mixing oxymuriate of potash with 
arsenic ? 

What effect docs it have on iron ? 

Of what use is arsenic ? 

What is an antidote for its poison ? 

What is chromium ? 

What are its characteristics ? 

With how many portions of oxygen will chromium 
combine ? 

What is the protoxide ? 

What is the deutoxide ? 

"What is the tritoxide or peroxide ? 

•Where is it found ? 



g 8 LYFRSB VCTION 

What is molybdenum ? 

What are its properties ? 

Does molybdenum unite with any of the metals t 

What are the oxides of molybdenum ? 

What is tungsten ? 

What are the oxides of tungsten ? 

What is the protoxide ? 

What is the effect of heating tungsten, with chlorine t 

What is columbium ? 

How is it procured ?.. 

W T hat is selenium ? 

Is selenium a conductor of calorie and electricity ? 

What is its affinity for oxygen £ 

What is selenic acid ? 

What are seleniurets ? 

What is osmium ? 

What are its characteristics T 

Does it unite with the metals ? 

What is the best test for osmium 8 



CHAP. XXX. 

0/ Rhodium Iridium — Uranium — Titanium — Cerium- — . 

Wodanium. 

1. Rhodium is a metal discovered in the ore of pla- 
tinum. 

2. It is not malleable. It unites with all the metals, 
except mercury. When alloyed with three times its 
weight of bismuth, copper or lead, the substances may 
be completely dissolved in a mixture of two parts by 



TO CHEMISTRY. 231 

measure of muriatic acid, and org of nitric. When lead 
is used, it is reduced by evaporation to an insoluble mu- 
riate, which then exhibits the rose colour ; from which 
circumstance, the name of the metal is derived. It is 
soluble in alcohol. 

3. Iridium is likewise extracted from the ore of pla- 
tinum, and is so named from the variety of colours ex- 
hibited in the oxide. It has been obtained in a state of 
purity, by heating* the muriate, which expelled the acid 
and oxygen. It is of a white colour, and perfectly infu- 
sible. 

4. It unites- with many of the metal?, forming al- 
loys. 

5. It unites with sulphur and forms a sulphuref, 
which is of a black colour, and consists of 100 iridium 
and 33.3 sulphur. 

6. Uranium is a metal discovered in a mineral, called 
Fechblende, where it exists in a state of sulphuret. It 
likewise occurs in the state of an oxide in green mica. 
and in the uranochre. 

• 7. Uranium is of a dark grey colour inclining to 
brown ; it is obtained in grains, forming* a porous mass. It 
requires a stronger heat to fuse it than manganese. 

8. There is -probably but two oxides of uranium ; 
the protoxide, which is -greyish black ; and the perox- 
ide, which is yellow. 

9. The oxide is soluble in dilute sulphuric acid, 
gentty heated, and affords lemon coloured prismatic crys- 
tals. Its solution in muriatic acid, in which it is but im- 
perfectly soluble, affords 3'eiiowish green rhomboidal 
tablets. Phosphoric acid dissolves it, but after some 
time, the phosphate falls down in a flocuient mass, of a- 
pale yellow colour. 

24* 



282 INTRODUCTION 

10. It combines with verifiable substances, and gives 
them a brown or green colour. With the usual flux, on 
porcelain, it produces an orang*e colour. 

1 1 . Titanium is a metal originally discovered in Corn- 
wall, Eng. and first called Menachanite. It is found also 
in a mineral, called red schorl, or titanite. 

12. It is in the form of agglutinated friable masses. — 
Crystallized, internally of a brilliant red. Infusible, un- 
alterable by water. Soluble in boiling sulphuric, muri- 
atic and nitric acids. 

13. It tarnishes on exposure to the air, and is oxi- 
dized when heated in contact with it. 

14. Titanium combines with three portions of 0x3'- 
gen. The protoxide is blue, the deutoxide red, and the 
peroxide white. 

15. It unites with phosphorus, forming a pale white 
compound of a metallic lustre, of a brilliant and granu- 
lated texture. It unites with iron, and forms an alloy. 

16. Cerium is a metal discovered by Hisinger and Be r- 
zelius, in a mineral found in a Swedish copper mine. 

17. To procure the oxide of cerium is easy ; but all 
attempts to reduce that oxide to a metallic state have 
failed. The metal appears to be volatile, and is dissi- 
pated by a violent heat, while a moderate heat is not 
efficient to reduce it. 

13. Cerium appears to be white and brittle. 

19. It is capable of two stages of oxidation, the white 
und the red. 

20. Alkalies do not act upon it ; but caustic potash 
in the dry way, takes part of the oxygen from the red 
oxide, so as to convert it into the white, without altering 
its nature. 

21. The oxides of cerium are soluble in the min- 
eral acids, and form salts, which are of a white or yel- 
low colour, and a sweetish taste. 



TO CHEMISTRY. 283 

22. The white oxide unites directly with tartaric 
acid, but requires an excess to render it soluble. 

23. JVodanium is a metal recently discovered in Wod- 
an pyrites, a mineral of Hungary, and so named from 
Woden, or Wodan, an ancient German deity. 

24. It has a bronze yellow colour. It is malleable ; 
its fracture is hackly *; it has the hardness of fluor spar ; 
and is strongly attracted by the magnet. 

25. It is not tarnished by exposure to the atmosphere 
at a common temperature ; but when heated, it is con- 
verted into a black oxide. 

26. The solution of this metal in acids is colourless, 
or at least has only a wine yellow tinge. Its r^drated 
carbonate is white. The hydrate precipitated by car- 
bonate of ammonia is indigo blue. 

27. Neither the alkaline phosphates nor arseniates, 
occasion any precipitate, when dropped into a saturated 
solution of the metal in an acid. Infusion of galls, like- 
wise, produces no precipitate. A plate of zinc throws 
down a black metallic powder from the solution of this 
metal in muriatic acid. Prussiate of potash throws down 
a pearl grey precipitate. 

28. Nitric acid dissolves with facility both the metal 
and its oxide, and the solution yields colourless needle 
form crystals, which readily dissolve in water. 

PRACTICAL QUESTIONS. 

What is rhodium ? 

What are its characteristics ? 

What is iridium ? 

Does it unite with any of the metals ? 

Does it unite with sulphur ? 

What is uranium ? 

How many oxides are there of uranium ? 



2$1 INTRODUCTION 

In what is the oxide soluble ? 

With what does the oxide combine ? 

What is titanium ? 

What are its characteristics ? 

What effect has the air upon it ? 

How many oxides are there of titanium ? 

With what does it unite ? 

What is cerium ? 

Is it procured in a metallic state ? 

What are its characteristics ? 

With how many portions of oxygen does it combine/? 

Do alkalies act upon it ? 

In what are the oxides of cerium soluble ? 

Does the white oxide unite with tartaric acid? 

What is wodanium ? 

What are its characteristics ?. 

What effect has the air upon it ? 

What are the solutions of this metal in acids % 

How is it precipitated from its solutions? 

What effect has nitric acid upon it? 



CHAP. XXXL 

Of Prussine : or Cyanogen. 

1. Prussine, or prussic gas, is what M. Gay Lussac 
terms cyanogen ; a word derived from the Greek, and 
literally signifies a producer of blue. But the production 
of blue can never be the effect of this substance on any 
other single body; but an indirect operation of it in con- 
junction with' iron, hydrogen and oxygen. This action 
has not been fully explained. 



TO CHEMISTRY. 285 

£. As this substance does not directly produce blue 
with iron, many chemists have relinquished the term cy- 
anogen, and as this substance, like chlorine and iodine, by 
its action on potassium produces flame, and like them i# 
acidified by hydrogen, the term prussine is thought ta be 
more appropriate. 

3. This substance was discovered and examined by 
M. Gay Lussac. 

4. By digesting red oxide of mercury with prussian 
blue, a cyanide or prusside may be obtained, perfectly 
neutral, which crystallizes in long four sided prisms, trun- 
cated obliquely. By repeated solutions and crystalliza- 
tions, it may be freed from a small portion of iron which 
adheres to it Or it may be boiled with red oxide of mercu- 
ry and the iron will be precipitated. The excess of oxide 
of mercury must be saturated with a little prussine or 
muriatic acid. The prusside thus formed is decomposed 
by heat to obtain the radical. 

5. When the cyanide is boiled with the red ox- 
ide of mercury, it dissolves a considerable quantity of the 
oxide, becomes alkaline, crystallizes no longer in prisms 
but in small scales, and its solubility in water appears a 
little increased. When evaporated to dryness, it is very 
easily charred, on this account it is necessary to employ 
the heat of a water bath. 

6. When the compound is decomposed by heat, it gives 
abundance of prussine mixed with carbonic acid gas. 
The prusside of mercury, when neutral and very dry, 
produces prussine ; but when moist,, it furnishes only car- 
bonic acid, ammonia and a large quantity of prussic acid 
vapour. 

7. When the prusside is used with excess of the pe- 
roxide, the same products are obtained, but in differ- 



286 INTRODUCTION 

ent proportions, together with azote and a brown 
liquid. 

8. To obtain pure prussine, the neutral prusside must 
be used in a state of perfect dryness. The other mercu- 
rial compound, is not, however, a sub prusside simply ; 
but a compound of the oxide of mercury and the prus- 
sine ; analogous to the brick coloured precipitate obtain- 
ed by adding a Jittle potash to the deuto-chloride of mer- 
cury, corrosive sublimate, which is a triple compound of 
chlorine, oxygen and mercury ; or a binary compound of 
oxide of mercury and a chloride of that metal. . These 
compounds maybe called oxy-prussida and. oxy-chlpridQ 
ofmercury. 

9. When the neutral simple mercurial prusside is ex- 
posed to heat in a small glass retort, or a tube closed at 
one end, it soon begins to blacken f appears to melt like 
an animal matter, and the prussine is disengaged in. 
abundance. This gas, from the commencement of the 
process to the end, is pure ; care must be taken, howev- 
er, not to raise the heat too high, so as to melt the glass * 
in that case a little azote will be disengaged. 

Observation, In this process mercury is sublimed with 
a considerable quantity of prussine, and there remains a 
charry matter, very light, and spongy, of the colour of 
soot. 

10. The prusside of silver gives out prussine when 
heated, but that of mercury is preferable and is more 
economical. 

11. Prussine is a permanently elastic fluid. Of a pe- 
culiar and penetrating smell. Soluble in water and im" 
parts to it a very sharp taste. The gas is combustible, 
and burns with a bluish flame, mixe ! with purple. Its 
specific privity compareJ with that of airis 1.8064. 100 
cubic inches weigh 5c J 295 grains. 



TO CHEMISTRY. 287 

12. Prussine is capable of sustaining a pretty high 
temperature without decomposition. 

13. Water absorbs about 4 1-2 times its volume. 

14. Sulphuric acid and oil of turpentine dissolve 
prussine in the same quantity as water. 

15. Prussine reddens tincture of litmus. On "heating 
the solution the gas is disengaged, mixed with a little 
carbonic acid, and the blue colour of the litmus is restor- 
ed. It is probable that the carbonic acid proceeds from 
decomposition of a small quantity of prussine and 
water. 

16. Prussine destroys the colour of red sulphate o 
manganese, a property which is not possessed hj prussic 
acid. Which is a proof of the superior activity of its el- 
ements. In the dry way, it separates the carbonic acid 
from the carbonates. 

17. Phosphorus, sulphur and iodine may be sublimed 
in prussine without producing any change on it, Its mix- 
ture with hydrogen was not altered by the same tempe- 
rature, or by passing electric shocks through it 

18. Copper and gold do not combine with prussine ; 
but iron, when heated almost to whiteness, partially de- 
composes it. The metal is covered with a si :ght coating 
of charcoal and becomes brittle. The undecompounded 
portion of the gas is mixed with nitrogen. It constitut- 
ed in one trial 0.44 of the mixture ; but in general it was 
-less. 

Platinum which had been placed at the side of the iron 
did not undergo any chunge ; neither its surface nor that 
of the -tube was covered with charcoal 

'19. Potassium acts but slowly on prussine in the cold* 
^because a crust is formed on its surface which prevents 
-the mutual action. On applying to the substance a spir] 
it lamp, the po4*s>ium speedily becomes -incandescent. 



£88 INTRODUCTION 

the absorption of the gas commences, the inflamed disc 
gradually diminishes, in a few seconds it disappears en- 
tirely, and the absorption is at an end. 

20. If a quantity of potassium be employed which 
will disengage 50 parts of hydrogen from water, it wil* 
be found that 48 or 50 parts of hydrogen will have dis- 
appeared. On treating the remainder with potash, there 
usually remains 4 or 5 parts of hydrogen, sometimes 10 
to 12. 

21. The compound of prussine and potassium is yel- 
lowish. It dissolves in water without effervescence and 
the solution is strongly alkaline. Its taste is the same 
as hydro cjanate of potash, of which it partakes of the 
properties. 

22. Prussine is very inflammable when exploded with 
about 2\ times its volume of oxygen. 

The detonation is very powerful, and the flame is 
bluish, like that of sulphur burning in oxygen. 

23. If 100 parts of .prussine be exploded, a diminution 
of volume takes place, which, when measured, is found 
to be from four to nine parts. When the residuum is 
treated with potash or barytes, it diminishes from 195 to 
200 parts, which are carbonic acid gas. The new resi- 
duum analyzed over water by hydrog'en, gives from 94 
io 98 parts of nitrogen, and the oxygen which it contains^ 
-added to that in the carbonic acid rs nearly equal to that 
which has been employed, 

24. 'From the above experiment it may be inferred 
that prussine contains a sufficient quantity of carbon to 
produce twice its volume of carbonx acid gas; that is, 
two volumes of the vapour of carbon with one of nitrogea 
condensed into a single volume. 

25. ff the above supposition be correct, the density of 
the radical derived from it ought to be equal to the den- 



TO CHEMISTRY, 289 

sity derived from experiment ; but supposing the density 
of air to be 1.00 twice that of the vapour of 

By experiment. 
Carbon is 0.8320 0.8332 

Nitrogen 0.9691 0.9722 



1.8011 1.8054 

26. By adding a volume of hydrogen to a volume of 
prussine, we obtain two volumes of prussic acid vapour, 
in the same way as by adding a volume of hydrogen to a 
volume of chlorine we obtain two volumes of muriatic 
acid gas. The same proportions hold with regard to the 
vapour of iodine, hydrogen and hydriodic acid. Hence 
it follows that the specific gravities of these acids are ex- 
actly equal to half the sum of the densities of their res- 
pective bases and hydrogen. 

27. M. Gay Lussac having introduced prusside of mer- 
cury into a glass tube, covered it with brown oxide of 
copper, and then raised the heat to a dull red. On heat- 
ing gradually the part of the tube containing the piusside 
it was gradually disengaged, passed through the oxide 
and the metal was completely reduced. On washing the 
gaseous products with a solution of potash, at different 
parts of the process, he obtained only from 0.19 to 0.30 
of azote ; instead of 0.33, which ought to have remained 
according to his former analysis. Presuming that some 
nitrous compound had been formed, he repeated the ex- 
periment, covering the oxide with a layer of copper fil- 
ings which he kept at the same temperature as the ox* 
ide. With this new arrangement, the results were very 
singular, for the smallest quantity of nitrogen which he 
obtained during the whole course of the experiment was 

25 



£90 INTRODUCTION 

32.7 for 100 of gas, and the greatest was 34.4. The 
mean of all the trials was 

Nitrogen 33.6 or nearly 1 

Carbonic acid 66.4 " 2 



100.00 

This shews that prussine contains two volumes ©f the 
ihe vapour of carbon, and one volume of azote or nitro- 
gen. 

28. In another experiment of Gay Lussac's instead of 
passing the prussine through the oxide of copper, he made 
a mixture of one part of the prusside of mercury, and 10 
parts of the red oxide ; after introducing it into a glass 
tube closed at one end, he covered it with copper filings, 
which he raised first to a red heat On heating the mix- 
ture successively, the decomposition went on with facility, 
the proportions of the gaseous mixure were less regular 
than in the preceeding experiment. 

Their mean was 

Nitrogen 34.6 instead of 33.3 

Carbonic acid 65.4 " 66.7 



100.0 
In another experiment he obtained 
Nitrogen 32.2 

Carbonic acid 67.8 



100.0 
Now the mean of these results gives 
Nitrogen 33.4 

Carbonic acid 66.6 

100,0 



TO CHEMISTRY, 291- 

This shows that what has been considered as a prus- 
siate of mercury, is in fact a prusside. 

29. When a pure solution of potash, not too concen- 
trated, is introduced into prussine, a rapid absorption 
takes place. If not quite saturated, it is scarcely tinged 
of a lemon yellow colour. But if the prussine be in ex- 
cess, we obtain a brown solution, apparently carbona- 
ceous. 

30. On pouring potash combined with prussine into a 
solution of protoxide of iron, and adding an acid, we ob- 
tain Prussian blue. At first it appears that the prussine is 
decomposed in this experiment, at the moment that it 
combines with potash, but this is doubted, for when this 
body is really decomposed by means of an alkaline so- 
lution, carbonic acid is produced, together with prussic 
acid and ammonia. But in pouring a solution of barytes 
into* a solution of prussine in potash, no precipitate is 
formed, which shews that no carbonic acid is present. 
On adding an excess of quicklime, no trace of ammonia 
is perceptible. And since no carbonic acid nor ammo- 
nia have been formed, water has been decomposed, con- 
sequently, no prussic acid is evolved. 

31. The instant an oxide is poured into a solution of 
prussine in potash, a strong effervescence of carbonic acid 
is produced, and at the same time a strong smell of prus- 
sic acid. 

Ammonia is likewise formed which remains combined 
with the acid employed, but when quicklime is added, it 
is made sensible. Since, therefore, we are obliged to add 
an acid in order to form a prussian blue, it is evident the 
prussine is not decomposed when added to potash. 

32. Soda, barytes and strontites produce the same ef- 
fect as potash. Hence we may conclude that prussine 
forms particular combinations with the alkalies, which 



2$2 INTRODUCTION 

are permanent, till some circumstance determines the 
formation of new products. 

33. These combinations are true salts, which may be 
regarded analogous to these formed with acids. In fact, 
prussine possesses acid characters. It contains two ele- 
ments of azote and carbon, the first of which, according to 
M. Gay Lussac, is strongly acidifying. Prussine reddens 
the tincture of litmus, and metalizes the bases. When it 
unites with hydrogen it acts as a simple tod}*, and produ- 
ces an acid. 

34. The metallic oxides do not seem capable of pro- 
ducing the same effect on prussine as the alkalies.^ M. 
Gay Lussac having precipitated proto sulphate of iron by 
an alkali, so that no free alkali remained, caused the ox- 
ide of iron while moist, to absorb prussine, and then ad- 
ded muriatic acid. But he did not obtain the slightest 
(race of prussianblue,though the same oxide to which he 
had added a little potash before adding the acid, produced 
it in abundance. 

35. From the above experiment, we are led to con- 
clude that the oxide of iron does not combine with prus- 
sine ; water impregnated with this gas never produces 
prussian blue with solutions of iron, unless we previously 
add an alkali. 

38. The peroxides of manganese and mercury, and 
the deutoxide of lead absorb prussine but slowly, but 
when water is added, the combination is much more rap- 
id. With the peroxide of mercury, a greyish white com- 
pound is formed, a little soluble in water. 

37. Prussine rapidly decomposes the carbonates at a 
dull red heat, and prussides of the oxides are oh- 
* ained. 

38. When prussine is passed through the sulphuret of 
barytes, it combines without disengaging the sulphur, 

♦ 



TO CHEMISTRY, £93 

assumes a brownish black colour and is very fusible. 
When thrown into watery a colourless solution is obtain- 
ed which gives a greenish brown colour to muriate ox' 
iron. That which remains insoluble contains considera- 
ble sulphate which is probably formed during the prepara- 
tion of the sulphuret of barytes. 

3£h When prussine is dissolved in the hydroguretted 
sulphuret of barytes, sulphur is precipitated, which is 
again dissolved, it becomes saturated with prussine and a 
liquid is obtained having a v ery deep brown colour. 

40. Prussine and sulphuretted hydrogen combine slowdy 
with each other. A yellow substance crystallized in fine 
needles is obtained, which is soluble in water,, does 
not precipitate nitrate of lead, but produces prussian- 
blue. 

41. Whenever ammoniacal gas and prussine come 
in contact, they act upon each other ; but some time elap- 
ses before the effect is complete. White thick vapours 
are at first disengaged, which soon disappear. .The di- 
minution of volume is considerable, and the glass, in 
which the mixture is made, becomes opaque, its inside 
being covered with a solid brown matter; 

Exp. On mixing 90 parts of prussine with 227 of ammonia, 
they will combine nearly in the proportion of 1 to I|> 
If thrown into water, it dissolves only hx very small pro* 
portions and gives a dark brown colour to the liquid, 
which produces no prassian blue with the salts of 
iron. 

42. When prussic acid is exposed to the action of a 
voltaic battery, with 20 pair of plates, much hydrogen 
gas is disengaged at the negative pole, while nothing ap- 
pears at the positive. This is because prussine is evolv* 
ed at that pole which remains dissolved in the acid, 

25* 



234 INTRODUCTION 

43. When an animal matter is calcined with potash 
or its carbonate, a prusside of potash is formed. It has 
been proved that potash separates, by the assistance of 
heat, the hydrogen of the prussic or hydrocyanic acid 
We cannot then suppose that the acid is formed while 
a mixture of potash and animal matters is exposed to, a 
high temperature. But we obtain a prusside of potash* 
and not of potassium. For potassium, when dissolved in 
water, gives only prussiate of potash, which is decom- 
posed by the acids, without producing ammonia and car- 
bonic acid ; while the prusside of potash dissolves in wa- 
ter without being altered, and does not give ammonia, 
carbonic acid, and prussic acid vapour, unless an acid be 
added. 

Observation. The above characteristics distinguish a 
prusside of a metal from a metallic oxide. 

44. By heating prusside of mercury in muriatic acid 
gas, Sir H. Davy obtained pure liquid prussic acid and 
corrosive sublimate. By heating iodine, sulphur and 
phosphorus in contact with prusside of mercury, com- 
pounds of these bodies with prussine may be formed. 

45. The compound of prussine and iodine is volatile 
at a very moderate heat, and on cooling collects in floc- 
culi, adhering together like oxide of zinc formed by com- 
bustion. It has a pungent smell, and very acrid taste, 

PRACTICAL QUESTIONS. 

What is prussine ? 

Why has the term cyanogen been relinquished, and 
that of prussine adopted ? 

How is prussine obtained ? 

How do you procure the prusside of mercury ? 

What is the effect when the cyanide is boiled with the 
red oxide cf mercury ? 



TO CHEMISTRY, 29 b 

When this compound is decomposed by heat, what is 
produced ? 

What is the effect when the prusside is used with ex- 
cess of the peroxide ? 

What is necessary in order to prodnce pure prussine ? 

What takes place when the neutral mercurial prusside 
is exposed to heat ? 

Is the gas, throughout the process pure ? 

Does any other metallic prusside give out prussine ? 

What are the properties of prussine ?■" 

Does heat decompose it ? 

How much does pure alcohol absorb ? 

What quantity does water absorb ? 

Do any other substances dissolve equally as much as 
water ? ^ v 

W r hat effect does prussine have on tincture of litmus ? 

W T hat property does prussine possess which prussic 
acid does not ? 

What effect has prussine on phosphorus, sulphur and 
iodine, when sublimed in it ? 

Do the metals combine with prussine ? 

Does potassium act on prussifle ? 

What are the properties of prussine and potassium ?' 

Is prussine inflammable ? 

Suppose 100 parts of prussine be exploded, what 
takes place ? 

What may be inferred from this experiment ? 

What will the density of the radical be ? 

When a volume of hydrogen is added to a volume of 
prussine, what is the result, and what do you infer? 

Who first established the analogy ? 

Relate the experiment of M. Gay Lussac to determine 
the constituents of prussine. 



£96 INTRODUCTION 

Relate the. other experiment of the same chemist, and 
the result. 

What does this experiment shew ? 

When a pure solution of potash is introduced into prus- 
sine, what is the effect ? 

How can you account fcr the production of prussian 
blue in the above process ? 

What other substances produce the same effect ? 

What do you infer from this ? 

Do the metallic oxides produce the same effect as al- 
kalies ? 

Does the oxide of iron combine with prussine ? 

What effect is produced by passing prussine through 
sulphuret of barytes ? 

What, when it is dissolved in the dydroguretted sul- 
phuret of barytes ? 

Does prussine combine with sulphuretted hydrogen ? 

Do ammonia and prussine have any effect on each 
other ? 

What follows, when prussic acid is exposed to the ac- 
tion of the voltaic battery ? 

What is formed whei* an animal matter is calcined with 
potash ? 

What is the argument on the subject ? 

How do you distinguish the prusside of a metal from a 
prusside of a metallic oxide ? 

What facts have been discovered by Sir H. Davy ? 

What are the properties of prussine and iodine in com-* 
bination ? 



TO CHEMISTRY. 2§7 



CHAP. XXXII. 



Of the nature and composition of Vegetables. 

1 . Organized bodies are those which are furnished 
hy nature with various parts, calculated to perform cer- 
tain functions connected with life, which bear the most 
striking and impressive marks of design, and are distin- 
guished by a vital principle, from which the various or- 
gans derive the power of exercising their respective 
functions. 

2. We know nothing of the principle of vitality but 
by its effects, nor by what means the organs are enabled 
to perform their functions either in the animal or vege* 
table departments. 

3. The simplest class of organized bodies, is that of 
the vegetable world. These are distinguished from the 
mineral creation, not only by their more complicated 
nature, but by the power which they possess wiihin 
themselves, of forming new chemical arrangements of 
their constituent parts by means of appropriate organs 
Though all vegetables are composed of carbon, hydro- 
gen and oxygen, with a few other occasional ingredients., 
they separate and combine these principles by their va- 
rious organs, in a variety of ways, and form with them 
different kinds of juices and solid parts, which exist 
ready made in vegetables, and may be considered as their 
immediate materials. 

4. Potash^ soda, lime, magnesia, silex r alumina, sul- 
phur, phosphorus, iron, manganese, and muriatic acid 9 
have been occasionally found in vegetables, but they oc- 
cur in very small quantities, and are scarcely more en- 
titled to be considered as belonging to them, than gold or; 



298 INTRODUCTION 

some other substances, which are said to have been pro- 
cured from their decomposition. 

5. There is no part of a plant which consists solely 
of one particular ingredient ; a certain number of vege- 
table materials must always be combined for the forma- 
tion of any particular part, and these combinations are 
carried on by sets of vessels, or minute organs, which 
select from other parts and bring together the several 
principles- required for the developement and growth of 
those particular parts,, which they are intended to form 
and maintain. It i& probable these combinations are car- 
ried on by chemical principles ; for it would militate 
against all established theories, in chemistry,- to suppose 
that the organs of plants could cause principles to com- 
bine which have no attraction for each other, nor can 
superior attraction yield to those of inferior power. — 
The organs of plants, probably, act mechanically by 
bringing into coatact those principles in such propor- 
tions, as will, by their chemical combination, form the 
vapious vegetable products, 

6. As long as a plant i& in a growing state, the three 
principal constituents,, carbon, ^hydrogen and oxygen, are 
so nicely adjusted: and connected together, that they 
are not susceptible of entering into other combinations, 
but no sooner does the principle of vitality cease, than 
this state of equilibrium is destroyed, a decomposition 
commences, and new combinations are formed,, and an 
order of attraction succeeds, similar to what takes place 
ia unorganized matter ; and plants eventually all return 
to their simple elements. 

7. In a chemical point of view there are two kinds 
©f analysis, of which vegetables are susceptible. First, 
that which separates them into their immediate materi- 
als ; such as sap, resin, mucilage, &c. Secondly, that 



TO CHEMISTRY. 299 

which decomposes them into their primitive elements, 
as carbon, hydrogen and oxygen. By the first analysis, 
we obtain the following products from vegetables. 

8. Sugar is obtained in the greatest abundance from 
the sugar cane. It is likewise procured from the sugar 
maple, beets, parsnips, carrots, and from the stalks of In- 
dian corn, zea maze. It crystallizes, is insoluble in wa- 
ter and alcohol Taste sweet. Soluble in nitric acid, 
and yields oxalic acid. 

9. SarcocoL, a concrete juice brought from Arabia and 
Persia. It does not crystallize. Soluble in water and 
ilcohoh Taste sweetish bitter. Soluble in nitric acid, 
jmd yields oxalic acid r 

10. Jlsparagin, a substance oblaiBed from asparagus. 
Crystallizes. Taste cooling and nauseous, Soluble in 
hot water ; insoluble in alcohol. Soluble in nitric acid, 
and convertible into bitter principle and tannin, 

1L Gum does not crystallize. Taste insipid. Solu- 
ble in water, and forms mucilage,, Insoluble in alcohol 
Precipitated by silicated potash. Soluble in nitric acid, 
and forms mucous and oxalic acid. 

1 2. Ulmin* a substance obtained from the elm. It 
does not crystallize. Taste insipid. Soluble in water, 
and does not form mucilage. Precipitated by nitric and 
oxymuriatic acids in the state of resin. Insoluble in al- 
cohol. 

13. Inulin is a substance obtained from elecampane, 
It is a white powder. Soluble in boiling water ; but 
precipitates unaltered after the solution cools Insoluble 
in alcohol. Soluble in nitric acid, and yields oxalic 
acid. 

14. Starch is obtained from grain, horse chesnuts* 
burdock roots, &c> It is a white powder. Insoluble in 
cold water. Taste insipid. Soluble in hot water; opaque 



300 INTRODUCTION 

and glutinous. Precipitated by an infusion of galls. Pre- 
cipitate redissolved in a heat of 120° F. Insoluble in al- 
cohol. With nitric acid yields oxalic acid and a waxy 
substance. 

15. Indigo is a substance obtained from a plant grow- 
ing in various parts x>f the world, called indigofera tinc- 
toria. It is a blue powder. Taste insipid. Insoluble in 
water, alcohol and ether. Soluble in sulphuric acid. — 
Soluble in nitric acid, and converted into bitter principle 
and artificial tannin. 

16. Gluten is a substance resembling gelatine, princi- 
pally found m the flour of wheat It forms a ductile 
elastic mass with water. Partially soluble in water ; 
precipitated by infusion of nutgalls and chlorine. Solu- 
ble in acetic and muriatic acid. Insoluble in alcohol. — 
By fermentation becomes viscid and adhesive, and then 
assumes the properties of cheese. Soluble in nitric acid, 
and yields oxalic acid. 

17. Aibumen is a substance found in the green feculae 
iof some plants, particularly those of the cruciform order. 
It is soluble in cold water. Coagulated by heat, and be- 
comes insoluble in hot water. Insoluble in alcohol. Pre- 
cipitated by infusion of nutgalls. Soluble in nitric acid. 
Soon putrifies, 

18. Fibrin is a peculiar substance, found in vegeta- 
bles and animals. It is tasteless. Insoluble in water and 
alcohol. Soluble in diluted alkalies, and in nitric acid. 
Soon putrifies. 

19. Bitter principle. Colour yellow or brown. Taste 
bitter. Equally soluble in water and alcohol. Soluble 
in nitric acid. Precipitated by nitrate of silver. 

20. Extractive matter. Soluble in water and alcohol 
Insoluble in ether. Precipitated by chlorine, muriate of 



Tt) CHEMISTRY 301 

tin, and muriate of alumina ; but not by gelatin. Dyes 
fawn colour. 

21. Tannin. Taste astringent. Soluble in water and 
-alcohol of specific gravity 0.810. Precipitated by gela- 
tin, muriate of alumina, and muriate of tin. 

22. Fixed oils. No smell. Insoluble in water and 
"alcohol. Form soaps with alkalies. Coagulated by 

earthy and metallic salts. Donotboilin a less tempera* 
tare than 600° F. 

23. Wax. Insoluble in water. Soluble in alcohol, 
«ther and oils. Forms soaps with alkalies. Fusible. 

21. Volatile oils. Strong aromatic smell. Insoluble 
in water. Soluble in alcohol. Liquid, Volatile. Oily. 
By nitric acid inflamed, and converted into a resinous 
substance. 

25. Camphor. Strong odour. Crystallizes. Very 
little soluble in water. Soluble in alcohol, oils and acids. 
Insoluble in alkalies. Burns with a clear flame, and vol- 
atilizes before melting. 

26. Birdlime. Viscid. Taste insipid. Insoluble in 
water. Partially soluble in alcohol. Very soluble in 
ether. Solution green. 

27. Resins. Solid. Melt when heated. Insoluble in 
water. Soluble in alcohol, ether and alkalies. Soluble 
m acetic acid. By nitric acid converted into artificial 
: tannin. 

28. Guaiacwn, possesses the character of resins ; 
but dissolve in nitric acid, and yields oxalic acid^ but no 
tannin. 

29. Balsams, possess the characters of the resins, 
but have a strong smell ; when heated, benzoic acid 
sublimes. It sublimes also when they are dissolved in 
sulphuric acid. They are converted by nitric acid into 
artificial tannin. 

m 



302 INTRODUCTION 

30. Caoutchouc, or India rubber. Very elastic. Inso- 
luble in water or alcohol. When steeped in ether re- 
duced to a pulp, which adheres to any substance in con- 
tact. Fusible. Very combustible. 

31. Gum resins, form milky solutions with water, 
transparent with alcohol. Soluble in alkalies. With ni- 
tric acid converted into tannin. Strong smell. Brittle. 
Opake. Infusible. 

32. Cotton, composed of fibres. Tasteless. Very 
combustible. Insoluble in water, alcohol and ether. So- 
luble in alkalies. Yields oxalic acid with nitric acid. 

33. Suber, or cork, burns bright, and swells. Con- 
verted by nitric acid into suberic acid and wax. Par- 
tially soluble in water and alcohol. 

34. Wood, composed of fibres. Tasteless. Insoluble 
in water and alcohol. Soluble in a weak alkaline lixivi- 
um. Precipitated by acids. Leaves much charcoal when 
distilled in a : red heat. Soluble in nitric acid, and yields 
oxalic acid. 

35. Jumeiin is a substance obtained from Ipecacuanha, 
It has no smell. Taste bitter and acrid. Soluble both 
in water and alcohol. Insoluble in ether. Not crystal- 
lizable. Precipitated by corrosive sublimate. j\cts as 
a powerful emetic. 

36. Fungin is the Meshy part of mushrooms. It seems 
to be a modification of woody fibre. 

37. Hematin is the colouring principle of logwood. — 
Soluble in boiling water, and forms an orange red, which 
becomes yellow as it cools. Excess of alkali converts it 
first to purple, then to violet, and lastly to brown. — 
Unites with metallic oxides, forming a blue coloured 
compound. Precipitated by gelatin. Reddens by per- 
oxide of tin and acids. 



TO CttfcMlSTHY. 303 

$& Nicotin is obtained from tobacco. Colourless. 
Has the taste and smell of the plant. Soluble both in 
water and alcohol. Volatile. Poisonous. Precipitated 
from its solution by tincture of galls. 

39. Pollenin is a substance obtained from the pollen 
of flowers. It is yellow.- Destitute of taste and smell. 
Insoluble in water," alcohol, ether, fat and volatile oils, 
and petroleum; Burns with flame. Soon becomes pu- 
trid on exposure to the air, 

The following' substances are considered as new vege- 
table alkalies. 

1. Aconita is a poisonous principle, extracted from 
the Aconitum napeUum, or Wolfsbane. 

2. Atropia is an alkaline principle, extracted from 
Jlir^a Belladona^. or deadly nisrht-shade. It is white, 
brilliant, crystallizes in long needles. Tasteless. But 
little soluble in water or alcohol. Resists a moderate 
heat. With acids, forms a neutral salt, and is capable of 
neutralizing a considerable portion of acid. 

3. Brucia, or bvucine is a substance extracted from 
the false augustum, or Brucea anti dysenterica. Soluble 
in 500 times its weight of boiling water,, and in 860 of 
cold Water. Taste exceedingly bitter, acrid and dura- 
ble in the mouth. Permanent in the air. Unites with 
the acids, and forms salts. 

4. Cicuta is a vegetable alkali, obtained from hem- 
lock. 

5. Datura is another alkaline substance, obtained 
from the Datura stramonium. 

6. Delphinia is an alkaline substance, obtained from 
stavesacre, or Delphinium staphy sagria. Taste bitter 
and acrid. When heated, melts, and on cooling becomes 
hard and brittle, like resin. Soluble sparingly in water. 



304 INTRODUCTION 

Soluble in alcohol and ether. Forms soluble neutral salts, 
with acids. 

7. Hyosciama is an alkali,., obtained from Hyosciamiis 
nigra, or henbane. Crystallizes in long prisms. Soluble 
in sulphuric or nitric acid, and forms characteristic salts. 
Vapour prejudicial to the eyes. Very poisonous. 

8. Morphia is an alkali, extracted from opium, of 
which it constitutes the narcotic principle. Soluble in 
82 times its weight of boiling water, in 36 times its 
weight of boiling alcohol, and in 42 times its weight of 
cold alcohol. Changes the infusion of brazil wood to a 
violet, and the tincture of rhubarb to a brown, h is so- 
luble in the acids, and forms salts. 

9. Picrotoxia is the bitter and poisonous principle of 
cocculus indices,, obtained in four sided crystals, of a whife 
colour. Taste intensely bitter. Soluble in water, alco-. 
hoi and sulphuric ether. Unites with the acids, and 
forms salts. It acts as an intoxicating poison. 

10. Strychnia is a substance from strychnos mix vomica. 
Crystallizes in very small four sided prisms, terminated 
by four sided low pyramids. Colour white. Taste bit- 
ter. Destitute of smell ; is not altered by exposure tQ 
the air. Neither fusible nor volatile, previous to de- 
composition. When taken into the stomach, it acts with 
great energy. 

11. Ver atria is an alkali, obtained from vtratrum sa- 
baiilla, or cevadiUa, veratrum album, or white hellebore,, 
and colchicum autumnale, or meadow saffron. White. 
Pulverulent. Destitute of odour. Excites violent sneez^ 
lag. Very acrid, but not bitter. Scarcely soluble in 
cold water. 



TO CHEMISTRY. 305 

PRACTICAL QUESTION. 

What are organized bodies ? 

Do we know any thing of the principle of vitality ? 

What is the simplest class of organized bodies ? 

How are these distinguished ? 

What substances have been found in vegetables ? 

Does any part of a plant consist of one particular in- 
gredient ? 

Why do not carbon, hydrogen and oxygen enter into 
other combinations while the plant lives ? 

How many kinds of analysis of plants are there ? 

What are the properties of sugar? 

Of Sarcocol ? 

Of Asparagin ? 

Of Gum ? 

OfUlmin? 

Of Inulin ? 

Of Starch ? 

Of Indigo ? 

Of Gluten ? 

Of Albumen ? 

Of Fibrin ? 

Of Bitter principle ? 

Of Extractive matter V 

Of Tannin ? 

Of fixed oils ? 

Of Wax? 

Of volatile oils ? 

Of Camphor ? 

Of Birdlime ? 

Of Resin ? 

Of Guaiacum ? '• 

Of Balsam ? 

Of Caoutchouc ? 
26* 



306 INTRODUCTION 

Of Gam Resin ? 

Of Cotton ? 

Of Suber ? 

Of Wood ? 

Of Emetin ? 

OfFungin ? 

Of Hematin ? 

Of Nicotin ? 

Of Pollenin ? 

What are the new vegetables alkalies f 

What are the properties of Aconita ? 

Of Atropia ? 

Of Brucia ? 

From what is Cicuta obtained ? 

From what is Datura obtained ? 

What are the properties of DelphiniaC 

Of Hyosciama ? 

Of Morphia ? 

Of Picrotoxia ? 

Of Strychnia ? 

Of Veratria ? 



CHAP. XXXIII. 

Of Colouring Matter — Decomposition of Vegetables — Fer- 
mentation. 

1. The colouring part of vegetables is that used for 
dyeing, calico printing, and the like. 

2. It is not found separate, but is combined with ex- 
tractive matter ; with gum, in which case, it is soluble 
in water. With farina, in this case, it is most soluble in 



TO CHEMISTRY. 30T 

sulphuric acid and with resins, when it requires alcohol, 
oil, or an alkali for solution. 

3. Colouring matter has a great affinity for alumina 
and the oxides of tin ; on which account, the solutions of 
these substances readily precipitate the infusion of col- 
ouring matter in water. 

4. The modes of obtaining and transferring the col- 
ouring matter from one substance to another, so that it 
shall be fixed, constitute the art of dyeing. 

5. The great variety of colours observed in dyed 
substances are reduced to four simple ones, viz. blue, ob- 
tained from indigo ; the red, afforded by madder, archil, 
brazil wood, cochineal, and some other substances ; yel- 
low, obtained from quercitron bark, sumach, tumeric, &c. 
and the black, obtained from a combination of iron with 
gallic acid. 

6. In dyeing, some colours are permanently attached 
to the fabric by merely boiling or dipping it in them, 
while others leave a mere stain, not permanent. 

7. These are to be fixed through the medium of a 
proper basis. The principal bases are alumina, and 
some of the metallic oxides in combination with several 
acids. 

8. Colours not permanent, are called adjective col- 
ours ; and those which are permanent, substantive. 

Exp. Take a little of the solution of indigo in sul- 
phuric acid, and add to it an equal quantity of carbonate 
of potash. Dip into it a piece of white cloth, it will 
become of a fine blue. Yellow cloth dipped into it will 
be changed to green, and red will be converted to a fine 
purple. 

9. Cochineal is naturally of a red colour, but it is us- 
ed for scarlet dyeing ; to obtain the scarlet hue, a tar- 
trate of potash is used as a base, and the basis by which 



303 INTRODUCTION 

it is fixed to the cloth is oxide of tin. It is an adjective 
colour. 

Exp. 1. Put a piece of white cloth into a decoction 
of cochineal, it will be simply stained. But add to it 
some tartrate of potash, and a little nitro muriate of tin, 
and it will afford a permanent scarlet colour. 

Exp. 2. The decoction of q uercitron bark is an ad- 
jective colour ; but by the aid of alumina as a base, we 
get a bright yellow. With the oxide of tin, all the shades 
from a pale lemon to a deep orange are formed ; and 
with the oxide of iron it gives a drab colour. 

Exp. 3. To a solution of carbonate of potash, add an 
equal quantity by weight of nitrate of iron. This will 
produce the permanent buff colour of the calico printer. 

Exp. 4. Equal parts of arnatto and potash of com- 
merce, will give the nankeen dye. 

Exp. 5. Take a piece of dark brown cloth, which 
has been dyed with fustic, and with a camel's hair pencil 
draw some figures on it with a solution of muriate of tin, 
the figures will quickly appear yellow, instead of brown. 

10. To dye any kind of stuff, i^hould first be clear- 
ed of all glutinous and greasy matters, by being washed. 
In some cases, it is to be whitened ; it is then to be dip- 
ped into a mordant, which is an intermediate substance, 
that has a greater affinity for the colouring matter than 
the cloth has, such as the muriate of tin, sulphate of 
alumina, &c. and then it is to be passed through the col- 
ouring liquid. 

11. Mordants are employed to give lustre, as well as 
durability to the colour. They must be so contrived as 
to have an affinity both for the colouring matter and the 
stuff itself. By a decomposition both of the mordant and 
the substance which holds the colouring matter in solu- 



TO CHEMISTRY. SO 9 

tion, the colour is precipitated on the base of the mor- 
dant, and adheres to it. 

12. Decomposition of vegetables takes place after the 
death of the plant. When vegetables cease to be pro- 
ductive, they cease to liv.e,and decomposition immediately 
ensues, which eventually resolves them into their constitu- 
ents, hydrogen, carbon, and oxygen. This process is slow- 
ly and gradually performed, during which time, a variety 
of new combinations are successively established and de- 
stroyed; but in each of these changes the ingredients of 
vegetable matter tend to unite in a more simple order of 
compounds, till they are ultimately brought to their ele- 
mentary state, or, at least to their most simple order o£; 
combinations. Thus vegetables are finally reduced to 
water and carbonic acid, the hydrogen unites with one 
portion of the oxygen to form water, while the carboa 
combines with another portion to fo HO- carbonic acid? 

13. Vegetables are susceptible of undergoing certain 
changes previously to the sti^, of putrefaction, which is. 
the last term of decomposition.. The vegetable decom- 
position is always attended by a violent internal motionr 
occasioned by the disengagement of one order of parti- ' 
cles, and the combination of another,. This is called fer^ 
mentation. There are several periods at which this pro-. 
cess stops, so that a state of rest appears to be restored 
and a new order of compounds fairly established. Mean& 
must be used to secure these new combinations in their 
active state, or their duration will be transient ; and a 
new fermentation will take place, by which the compound 
last formed will be destroyed, and another and less cohk 
plex order will succeed. 

14. Fermentation appears to be only the successive 
steps by which a vegetable descends to its final dissolu- 
tion, 



330 INTRODI/CTrON 

15. There are several circumstances required to pro- 
duce fermentation. Water and a certain degree of heat 
are both essential to this- process, in order to weaken the- 
force of cohesion of the particles and cause them to sep- 
arate, that the new chemical affinities may be brought 
into action. 

16. The several fermentations derive their names 
from their principal products r as the saccharine, the vinous. 
the acctovj. and jmtrej active. 

17. The saccharine fermentation is not confined to 
the decomposition of vegetables , . as it commonly takes 
place in plants in a living state. 

18. Sugar is not secreted from sap in the same man- 
ner asfecula, mucilage, oil and other ingredients of vege- 
tables, but it is formed rather from these materials rfrarr 
the sap itself, and it is developed at particular periods, as 
fruits, which do not become sweet until ripe, sometimes 
even after they have been gathered. Hence it appears 
that life is not essential to u/e formation of sugar, but pro- 
ceeds from the destruction of the previous order of com- 
binations, which must depend upon fermentation, while 
mucilage, fecula and other vegetable materials are secret- 
ed from sap by appropriate organs, consequently J depend 
upon the vital principle. 

19. The ripening of fruits is their first step towards 
decomposition as well as their last towards perfec- 
tion. 

20. A change analogous to the saccharine fermenta- 
tion takes place during* the cooking of certain vegetables, 
as parsnips, carrots, &c. in which sweetness appears to be 
developed during heat and moisture. The same process 
also takes place in seeds previously to their sprouting. Tl e 
materials of the seed must be decomposed, and the seed 
disorganised before a plant can sprout from it. 



TO CHEMISTRY. 313 

£1. Seeds contain fecula, oil and a little mucilage ; 
these substances are destined for the sustenance of the 
future plant, it is necessary that thej undergo some 
change before they become fit for this function. The 
seeds when buried in the earth with a certain degree of 
moisture and temperature absorb water, which dilates 
them, separates their particles, and commences a new or- 
der of attractions, the product of which is sugar. The 
substance of the seed is thus softened, sweetened and con- 
verted into a milky pulp, appropriated to the nourish- 
ment of the embryo plant, 

22. The saccharine fermentation of seeds is produced 
for the purpose of maltingc 

Exp. A quantity of barley is soaked in water for tw© 
or three days, the water being afterwards drained off, the 
grain heats spontaneously, and sometimes artifical heat is 
employed .; it swells, bursis,-sweetens, shews a disposi- 
tion to germinate, and actually sprouts sometimes, to the 
length of an inch in one night. The process is then stop- 
ped by putting it into a kiln, where it is dried by a gentle 
heat In this state it constitutes the substance called 
malt. 

23. The saccharine fermentation takes place like- 
wise in hay, in stacks, and sugar is the product ; on this 
principle it is that old hay is more nourishing for cattle 
than new. 

24. The second kind of fermentation is the vinovs, sc 
called from wine being its product. 

25. The saccharine fermentation appears to be favorable 
if not absolutely necessary to the vinous fermentation, so 
that if sugar be not developed during the life of the plant, 
the saccharine fermentation must be artificially produced 
before the vinous can take place. This is the case with 
barley, which does not yield any sugar until it is made 



3 1 2 INTRODUCTION 

into mait ; and it is in that state only, that it is suscepti- 
ble of undergoing the vinous fermentation by which it is 
converted into beer. 

26. The consequence of the vinous fermentation is 
the decomposition of the saccharine matter, and the for- 
mation of a spirituous liquor from the constituents of the 
sugar. 

27. In order to promote this fermentation, not only 
water and a certain degree of heat are necessary, but also 
some other vegetable ingredients besides sugar,as fecula, 
mucilage, acids, salts, extractive matter, &c. all of which 
seem to contribute to this process, and give to the liquor 
its peculiar taste. 

Illustration. On this principle it is that wine is not ob- 
tained from the fermentation of pure sugar ; but fruits 
are chosen for that purpose, as they contain the vegeta- 
ble ingredients which promote the vinous fermentation 
and ^ive its peculiar flavour. 

28-. It is the proportion in which sugar is mixed with 
other vegetable ingredients that influences the produc- 
tion and qualities of wine. 

Observation, it is found that the juice of the grape 
not only yields the greatest proportion of wine, but of 
the most grateful flavour. 

29. The following changes happen during the vinous 
fermentation, 

The sugar is decomposed and its constituents are re- 
combined into two new substances ; the one a peculiar 
liquid substance called alcohol, or spirits of wine, which 
remains in the fluid ; the other, carbonic acid gas, which 
escapes during the fermentation. Alcohol, therefore ap- 
pears to constitute the essential part of wine. And the 
varieties of strength and flavour of different kinds of wine 
are to be attributed to the different qualities of fruits 



TO CHEMISTRY, 313 

from which they are obtained, independently of the 
sugar. 

30. The principal difference between alcohol and sug- 
ar consists in this. Sugar is composed of carbon, hydro- 
gen and oxygen ; during the formation of alcohol, carbon. 
ic acid is extracted from this, consequently alcohol con- 
tains less carbon and oxygen than sugar does, of course 
hydrogen is the prevailing principle ; which accounts for 
the lightness and combustible property of alcohol, and of 
spirits in general, all of which consist of alcohol various- 
ly modified 

31. At the commencement of the vinous fermentation 
heat is evolved, and the liquor swells considerably, in 
consequence of the formation of carbonic acid. If the 
fermentation be checked by putting the liqour into casks 
before the whole of the carbonic acid is evolved, the wine 
is brisk, like champagne,from the carbonic acid, vulgarly 
called fixed air, its taste is sweet, from the sugar not be- 
ing completely decomposed. 

32. During the decomposition and recomposition at- 
tending fermentation, a quantity of caloric may be disen- 
gaged, sufficient both to develope the gas, and to effect 
an increase of temperature ; when the formation is com- 
pleted, the liquor cools and subsides, the effervescence 
ceases, and the thick, sweet, sticky juice of the fruit is 
converted into a clear, transparent, spirituous liquor, cal- 
led wine* 

33. When wine of any kind is submitted to distillation, 
it is found to contain brandy, water, tartar, extractive col- 
ouring matter, and some vegetable acid. 

34. Brandy is a mixture of alcohol and water, the al- 
cohol may be separated by re-distilling the brandy. 

35. Brandy in its pure state is colourless, but in com- 
merce it is of a reddish yellow tint, sometimes made so 

27 



314 iictrodi; CTION 

by art, and at other times it extracts a colouring matter 
from the casks. It is usually coloured with a little burnt 
sugar. Brandy may be obtained from malt in a state ©^ 
fe mentation. 

36. Rum is distilled from the juice of the sugar cane 
which contains so great a quantity of sugar that it yields 
more alcohol than almost any other vegetable. Molasses 
which is extracted from the bruised cane by means of 
water, after it has been pressed for making sugar, is fer- 
mented and submitted to distillation, the product of which 
is rum, „ 

37. Arrack is the product of the distillation of fermen- 
ted rice 

38. Gin and whiskey are extracted from fermented 
grain. The peculiar flavour of gin is owing to juniper 
berries, which are distilled with the grain. Whiskey is 
likewise obtained from potatos in a state of fermenta- 
tion. 

39. The lees of wine consist of tartrate of potash and 
extractive matter; tartar exists in the juice of the grape 
and many other vegetables, and is developed only by the 
vinous fermentation ; during which it is precipitated, and 
deposits itself on the internal surface of the cask. When 
purified from foreign ingredients it is called cream of tar- 
tar, which is much used in medicine and the arts. 

PRACTICAL QUESTIONS. 

What is the colouring part of vegetables ? 
How is it found ? 

Has it any affinity for other substances ? 
What constitutes the art of dyeing? 
How many simple vegetable colours are there ? 
Are colours permanently attached to the fabric in dye- 
ins: ? 



TO CHEMISTRY. 31£> 

How are colours to be fixed on the stuffs ? 

What are adjective and substantive colours ? 

For what is cochineal used ? 

What is the process of dyeing any kind of stuff? 

What is the use of mordants ? 

When does decomposition take place in vegeta- 
bles? 

Do vegetables undergo any change previously to the 
state of putrefaction ? 

What is fermentation ? 

What is requisite for fermentation? 

What are the several fermentations? 

Is the the saccharine fermentation confined to the de- 
composition of vegetables ? 

Is sugar secreted from sap ? 

What is the first step towards decomposition ? 

How are seeds appropriated to the nourishment of the 
embryo plant ? 

What is malting? 

Does saccharine fermentation take place in hay? 

W T hat is the second kind of fermentation ? 

What appears necessary to the vinous fermenta 
tion ? 

What is the consequence of the vinous fermenta- 
tion ? 

What is necessary to promote this fermentation ? 

What influences the production and quality of wine ? 

What changes happen during the vinous fermenta- 
tion ? 

W^hat is the difference between alcohol and sugar? 

What phenomena takes place during fermenta-. 
tion ? 

Why is heat evolved during this operation ? 

What is wine found to contain?- 



3 1 G INTRODUCTION 

What is brandy ? 

Whence is the yellow tint of brandy obtained* 

Whence is rum obtained ? 

What is arrack ? 

From what are gin and whiskey obtained? 

Of what do the lees of wine consist? 

Wliat is tartar when purified ? 



€HAP. XXXIV. 

Continuation of Fermentation, 

1. In order to obtain alcohol perfectly fr<*e from wa- 
ter, it is necessary that it be rectified several times ; after 
which some muriate of lime should be added, in order to 
absorb any water that may remain. This should be ad- 
ded until it ceases to be moistened, inconsequence of the 
absorption of water. After which it should be redistilled 
in a water bath. 

2. As alcohol is much lighter than water, its specific 
gravity is adapted as the tes; of its purity. 

3. The chemical properties of alcohol are important 
and numerous. It is one of the most powerful chemical 
agents, and is particularly useful in dissolving a variety 
of substances which are not soluble by water nor heat- 
It dissolves volatile oils, and forms what are called essen- 
ces. It dissolves copal and mastic, and forms varn- 
ishes. 

4. Alcohol has a great tendency to combine with wa- 
ter, and this is so strong that when water is added to a 



TO CHEMISTRY. 317 

solution of gam in alcohol, the alcohol combines with the 
water and the gum is precipitated. 

Observation. On this principle it is that if water be ad- 
ded to tinctures and elixirs, they immediately become tur- 
bid; as when added to a solution of camphor. 

5. The addition of water to alcohol produces heat? 
and a diminution of bulk, which is supposed to be caused 
by a mechanical penetration of particles, by which latent 
heat is forced out, . 

6. Alcohol is extremely combustible ; and will burn? 
at a moderate temperature. 

7; Alcohol in combustion produces much flame but no 
smoke, which arises from its combustion being complete. 
The great quantity of flame proceeds from the combus- 
tion of carburetted hydrogen, - It will also burn in a lamp 
without a wick, it takes fire atso low a temperature that 
this assistance is not required to concentrate the heat and 
Tolatiliize the fluid. The rapidity of the combustion oi 
alcohol may be much increased by first volatilizing it, as 
is exhibited in the self acting blow pipev- 

8, The products of the combustion of alcohol consist, 
in a great proportion, of water, and a small quantity of 
carbonicacid; there is no smoke, or fixed remains, what- 
ever. 

Illustration. The oxygen which the alcohol absorbs in- 
huming, converts its hydrogen into water, and its carbon 
into carbonic acid gas, and in this way it is completely 
consumed. 

-96 If 1 00 parts of alcohol be burnt in a chimney, which 
communicates with the worm pipe of a distilling appara- 
tus, the product which is condensed will be found to be 
136 parts of water. 

10. If one part of alcohol be mixed in a retort, with * 
four of sulphuric acid, and exposed to a moderate heat, a 
27* 



318 INTRODUCTION 

ga** is produced which is called heavy carburetted or 
per-carburretted hydrogen, called also olefiant gas. Its 
specific gravity is 0,978. 100 cubic inches weigh 28.80 
grains. 

11. It possesses all the mechanical properties of air. It 
is invisible and void of taste and smell, after being wash- 
ed. When passed through a porcelain tube, heated to 
a cherry red, it lets fall a portion of charcoal, and nearly 
doubles its volume. At a higher temperature it deposits 
more charcoal, and augments in bulk. At the greatest 
heat to which we can expose it, it lets fail almost the 
whole of its carbon,and assumes a volume 3^ times great- 
er than it had at first. These remarkable results have 
led to the conclusion that hydrogen and carbon combine 
in many successive proportions. 

12. The transmission of a series of electric sparks 
through olefiant gas, produces a similar effect with that 
of simple heat. 

13. Olefiant gas burns with a splendid white flame= 
When mixed with three times its bulk of oxygen, and. 
kindled by a taper or electric spark, it explodes with 
great violence, and four volumes are converted into two 
volumes of carbonic acid. 

14. Ether is a substance obtained from alcohol, of which- 
it forms the lightest and most volatile part. In order to 
obtain it, the alcohol must be decomposed ; a certain pro- 
portion of carbon must be extracted, which is effected 
by the action of some acid on the alcohol. The 
acid and carbon remain at the bottom of the vessel, 
whilst the decarbonized alcohol flies off in the form of a 
condensible vapour, called ether. That which is most- 
ly used is obtained by the action of sulphuric acid on al- 
cohol. 



TO CHEMISTRY. 319 

Exp. When strong sulphuric acid is poured on an 
equal weight of alcohol, the fluids unite with a hissing 
noise, and the production of heat, at the same time that 
a fragrant vegetable smell is perceived, in some measure 
resembling that of apples, which is ether. 

15. Sulphuric ether is a very fragrant, light and vol- 
atile fluid. Its evaporation produces extreme cold. It 
is highly inflammable, and burns with a more luminous- 
flame than alcohol. It freezes at — 46° F. It dissolves 
essential oils, resins, camphor and caoutchouc readily. — 
It boils in the atmosphere at 98° F. and in vacuo at — 
20°. The density of its vapour is 2.586, that of air being 
1. Ether admitted to any gas standing over mercury, 
doubles its bulk at atmospheric temperatures. If oxygen 
be thus expanded with ether, and then mixed with three 
times its bulk of pure oxygen, it explodes on being kind- 
led, forming carbonic acid and water. By detonating 
such a mixture, M. dc Saussure has inferred ether to 
consist of 

Hydrogen 14.40 

Carbon 67.98 

Oxygen 17.62 



100.00 
These proportions per cent, correspond to 
Oleflant gas 80.05 
Water 19.95 



100.00 

16. By passing ether through an ignited porcelain 
tube, it is resolved into olefiant gas, a viscid volatile oil, 
a little concrete oil, charcoal and water. 

17. Ten parts of water combine with one of ether. 



323 IS TR ODU CTIODf 

18. Sulphuric acid converts ether into steed, oil cj- 
wine. 

19. If a very little ether be thrown iata a large bot~ 
tie containing chlorine, a white vapour soon rises, fol- 
lowed by explosions and flame. Charcoal is deposited 
and carbonic acid is formed. 

20. If a few drops of ether be poured into a wine 
glass, and a fine platina wire be coiled and heated al- 
most to redness, then held suspended in the glass, close 
to the surface of the ether, the wire soon becomes in- 
tensely red hot) and remains so until the ether be ex- 
hausted. On this principle is constructed the Apldogisik 
lamp, or lamp without flame. 

Illustration.* This is owing to a very peculiar proper- 
ty of the vapour of ether, and many other combustible 
gaseous bodies.. At a certain temperature, lower than 
that of ignition, these vapours undergo a slow and imper- 
fect combustion, hi which light is not emitted in any sen- 
sible degree, yet a quantity of caloric is extricated suf- 
ficient to react upon the wire and make it red hot ; the 
wire in its turn keeps up the effect as long as the emis 
sion of vapour continues. 

Observation. To perform the above experiment, pla- 
tina wire is absolutely necessary, because iron or steel 
being much better conductors of heat than platina, the 
heat is carried off too fast by those metals to allow the 
accumulation of caloric necessary to produce the effect. 

21. Alcohol is extensively used in pharmacy, chemis- 
try and the arts, and ether in medicine, though when 
taken in excess, it produces effects similar to those of in- 
toxication. 

22. Acetous fermentation is so called, because it con- 
verts wine into vinegar, by the formation of acetous acid, 
which is the basis, or radical of vinegar. 



TO CHEMISTRY. 324 

23. As the acidifying principle is oxygen, the contact 
of air is essential to this fermentation. In order to ob- 
tain pure acetous acid from vinegar, it must be distilled 
and rectified by certain processes. A good way is to ex^ 
pose vinegar to a temperature of about 20° for one night, 
and after separating the ice, distil the liquor. 

24. Vinegar may be obtained from wood ; it was for- 
merly called pyroligneous acid, but it is found when puri- 
fied to be common vinegar ; for this purpose it should 
be mixed with sulphuric acid, manganese, and common 
salt, and afterwards distilled over. 

25. Whenever a vegetable substance turns sour, it 
has ceased to live ; the acetous acid is developed by 
means of the acetous fermentation, in which the sub- 
stance advances a step towards its final decomposition. 

26. Any substance that has undergone the acetous 
fermentation, will readily excite it in one that is suscep- 
tible of that process. Thus, if vinegar be added in small 
quantities to wine, that is intended to be acidified, it will 
absorb oxygen more rapidly, and the process be com- 
pleted much sooner than if left to ferment spontaneously. 
Thus yeast, which is the product of the fermentation of 
beer, is used to excite and accelerate the fermentation 
of malt, which is to be converted into beer, as well as 
that of paste, which is to be made into bread. 

27. Bread, by undergoing the acetous fermentation, 
acquires a certain savour which serves to correct the 
heavy insipidity of flour, and may be considered as the 
first stage of acidification ; if the process were carried 
further, the bread would become decidedly acid. 

Observation. Some chemists do not consider the fer- 
mentation of bread as the acetous, but suppose that it is 
a fermenting process peculiar to that substance, which 
they have denominated panary fermentation. 



32& INTRODUCTION 

28. The putrid fermentation is the final operation ©£ 
nature. It is the last step towards reducing bodies to 
their simplest combinations. 

29. To effect this decomposition, a certain degree of 
moisture is necessary, and a sufficient degree of heat, 
together with access of air. For it is well known, that 
dead plants may be preserved by drying, or by the total 
exclusion of air for any length of time. 

30. If we attend minutely to the decomposition of 
plants from their death to their final dissolution, we 
shall generally find a sweetness developed in the seeds, 
and a spiritous flavor in the fruits, which have under- 
gone the saccharine fermentation, previously to the dis- 
organization and separation of the parts. 

Illustration. Apples, when over ripe, have a kind of 
spirituous taste, just before they become rotten. This is 
occasioned by the vinous fermentation, which has suc- 
ceeded the saccharine, and if we follow up these change 
es attentively, we shall find the spirituous taste followed 
by acidity, previously to the fruit passing to the state of 
putrefaction. Leaves which fall, in autumn, do not im- 
mediately undergo a decomposition, but are first dried ; 
but when the rain sets in, ..fermentation, commences, their 
gaseous products are evolved into the atmosphere, their 
fixed remains are mixed with the earths,. Ihey soon min- 
gle with the dust, and afford a pabulum for future plants. 

31. The dry rot, which attacks beams of houses, may 
at first sight, be thought to bs an objection to the above 
theory, because a- current of air prevents it But this 
must not be in such proportion to the moisture as to 
dissolve the latter, and this is- generally the case, when 
the rotting of wood is prevented or stopped by the free 
access of air. But dry rot, is not a true process of pu- 
trefaction. It is supposed to depend on a peculiar kind^ 



TO -CHEMISTRY. 32S 

of vegetation, which, by feeding on the wood, gradually 
destroys it. 

32. The process of making compost manure, depends 
upon the putrid fermentation. Straw and other vegeta- 
ble matters undergo the putrid fermentation much more 
rapidly when mixed with animal substances ; much heat 
is evolved during this process, and a variety of volatile 
^products are disengaged, as carbonic acid, hydrogen gas, 
and sulphuretted hydrogen. When all these gases have 
been evolved, the fixed products, consisting of carbon, 
salts, potash, &c. form a kind of vegetable earth, which 
is composed of those elements which form the immedi* 
ate materials of plants, and is much more active than 
dung in its recent state. 

33. Petrified vegetables, as they are called, are real- 
ly stone, consisting principally of silex. The process is 
this., when a vegetable substance is buried under water, 
or in wet earth, it is gradually decomposed. As each 
successive part of the vegetable is destroyed, its place is 
supplied by a particle of silicious earth, conveyed thither 
by the water. In process of time the vegetable is en* 
tireJy destroyed, and its place supplied by the siiex, hav- 
ing assumed its form and apparent texture, producing an 
appearance, as if the vegetable was turned to stone. 

Observation^ It is impossible that either vegetables or 
animals should be turned to stone. They may be re- 
duced by decomposition to their constituent elements, 
but cannot be changed to elements that do not enter into 
their composition. 

34. When vegetables ^re buried in the sea, or in the 
-earth, totally excluded from the air, they are subject to 
a peculiar change, by which they are converted into a 
new class of compounds, called bitumens. 



324 INTRODUCTION" 

35. Bitumens are vegetables so far decomposed as to 
retain no organic appearance ; but their origin is easily 
detected by their oily nature, their combustibility, the 
products of their analysis, and the impression of the form 
of leaves, grains, fibres of wood, and even of animals, 
which are frequently exhibited in different specimens of 
coal. 

36. Bitumens are sometimes of an oily liquid consist- 
ence, as the substance called naphtha. But they are more 
frequently solid, as asphaltum and jet, 

37. Naphtha is a light, thin, colourless oil, and highly 
odoriferous. It is found on the surface of water in cer- 
tain springs in Italy, and on the shores of the Caspian 
Sea. It is about one quarter lighter than water. It is 
very inflammable, and burns with a penetrating smell, 
and much smoke. By long exposure to the air, it be- 
comes thick, and passes to the state of petroleum. It ap- 
pears to be composed of carbon 82.2 and -(- hydrogen 
14.8 

38. Naphtha being destitute of oxygen, renders it the 
most proper liquid for preserving potassium ; because it 
has so great an affinity for oxygen, that it seizes it when- 
ever it comes in contact with it. 

39. Asphaltum is a smooth, hard, brittle, black or 
brown substance, which breaks with a polish, melts easi- 
ly when heated, and when pure, burns without leaving 
any ashes. It is found in different parts of the world, 
but in the greatest quantity on the shore of the Dead 
Sen. 

Observation. The Egyptians used asphaltum in em- 
balming the dead, tinder the name of mimiia minemlis, 
for which it is well adapted. It was used for mortar at 
Babylon, 



TO CHEMISTRY. 325 

40. Jet is harder than asphaltum, and susceptible of 
50 high a polish, that it is used for many ornamental pur- 
poses. It is composed of 

Carbon 75 

Bitumen 22 

Earth 2 ; 

Water 1 

100 
Its specific gravity is 1,3. 

41. Petroleum is a bituminous substance, thicker than 
naptha, has a greasy feel, is wholly^ or in part, trans- 
parent, and a little heavier than naptha. It is very high- 
ly inflammable, and has the property of combining with 
fat and essential oils, with resins, camphor and sulphur ; 
and when rectified, it dissolves caoutchouc. 

4&. Mineral tar is thicker and more viscid than pe- 
troleum, and of a reddish or blackish brown colour ; in 
its chemical properties, it resembles petroleum. 

43. Mineral pitch is extremely inflammable, of a 
brownish or blackish colour ; it is nearly twice as heavy 
as that of water. 

44. Coal is a bituminous substance, which seems to 
be composed of tnineral and animal substances, It ap- 
pears to consist principally of vegetable matter, mixed 
with the remains of marine animals and marine salts.— 
It occasionally contains a quantity of sulphuret of iron, 
commonly called pyrites. 

45. Coke is a kind of fuel, artificially prepared from 
coals, by means of charring or burning in close vessels, 
to expel the volatile parts. It is composed of carbon 
with some earthy or saline ingredients. 

46. Amber is considered as a bitumen, called by the 
ancients, Electrum, whence the term electricity, because 

28 



326 INTRODUCTION 

it is peculiarly, and was once supposed to be exclusively 
electric. 

47. It is found in mines in some parts of Prussia, and 
sometimes floating on the sea. 

48. It is a hard, brittle, tasteless substance, some- 
times perfectly transparent, but -mostly semi-transparent 
or opaque, and of a glossy surface. It is found of all 
colours, but chiefly yellow or orange. Its specific grav- 
ity is from 1.0G5 to 1.100. Its fracture is even, smooth 
and glossy. It is fusible at 550° F. It consists of an oil 
and an acid, the former is called oil of amber, the latter 
succinic acid. 

Observation. By some experiments made on the ef- 
fects of light on amber, Dr. Brewster has been led to 
conclude that it is an indurated vegetable juice. 

19. Peat or turf, is composed of the remains of vege- 
table organization, and consists in a great measure of the 
fibres of mosses, with the branches and roots of trees. — 
It is extremely inflammable in the open air, and when 
distilled in close vessels, yields products similar to those 
of coal. 

' PRACTICAL QUESTIONS. 

How can pure alcohol be obtained ? 

What is adopted as the test of the purity of alcohoH 

What are the chemical properties of alcohol ? 

Has alcohol any affinity for water ? 

What is the effect of adding water to alcohol ? 

Is alcohol combustible ? 

What are the phenomena of the combustion of alco- 
hol ? 

What are the products of the combustion of alcohol ? 

How much water will 100 parts of alcohol produce 
by combustion ? 



TO CHEMISTRY. 3^7 

How is olefiant gas formed ? 

What are its properties ? 

How can a similar effect, as that of simple heat, be 
produced on olefiant gas V 

What appearances are produced in the combustion of 
olefiant gas ? 

What is ether ?'. 

What are the properties of sulphuric ether ? 

What is the effect of passing ether through an ignited 
porcelain tube f 

How many parts of water combine with ether ? 

Into what does sulphuric acid convert ether ? 

What is the effect of chlorine on ether ? 

How do you perform the experiment which illustrates 
the principle of the aphlogislic lamp ? 

W r hy will not iron and steel answer ? 

Is alcohol much used ..?. 

What is the acetous fermentation ? 

What is necessary for this fermentation ? 

How do you obtain it pure ? 

Can viuegar be obtained from wood ? 

When is the acetous acid developed ? 

How can the acetous fermentation be excited ? 

What does bread acquire by the acetous fermentation : 

What is the putrid fermentation ? 

What is necessary to effect this decomposition ? 

What shall we generally find by attending minutely to 
the decomposition of plants ? 

How do you illustrate this ? 

Is not the dry rot an exception to this theory ? 

Upon what does the process of making compost de- 
pend ? 

What are petrified vegetables ? 



328 INTRODUCTION 

What is the effect of burying vegetables in the sea r or 
at great depths in the earth ? 

What are bitumens ? 

Are they of different consistencies ? 

What is naptha ? 

Why is naptha best calculated for preserving potas- 
sium ? 

What is asphaltum ? 

What is jet ? 

W r hat is petroleum ? 

What is mineral tar ? 

What is mineral pitch ? 

What is coal ? 

What is coke ? 

What is amber ? 

What is peat or turf? 



CHAP. XXXV 

Of Vegetation* 

1. The most obvious difference between animals and 
vegetables is, that the former are in general capable of 
conveying themselves from place to place ; whereas 
vegetables being fixed in the same place absorb by means 
of their roots and leaves, such support as is within their 
reach. This appears to be air and water. 

2. The greatest part of the support of animals are 
the products formed in the vegetable department. The 
products of these two departments in the hands of the 
chemist, are remarkably different 



ro CHEMISTRY. 329 

3. One of the most distinctive characters appears to 
be the presence of nitrogen or azotic gas, which may he 
extricated from animal substances by nitric acid, and en- 
ters into the composition of ammonia, afforded by de- 
structive distillation. 

4. It was long supposed that ammonia was exclusive- 
ly confined to the animaLdepartment, but it is now found 
that certain plants afford it, 

5. The nutrition or support of plants appears to re- 
quire water, earth T light and air. Various experiments 
have been instituted to shew that water is the only ali- 
ment which the root draws from the earth. 

Illustration. Von Helmont planted a willow weighing 
fifty pounds, in a certain quantity of earth, covered with 
sheet lead. It was watered for five years with distilled 
water, and at the end of. that time r .the tree weighed 169 
pounds, three ounces-, and the earth in which it had veg- 
etated was found to have suffered a loss of only three 
ounces. Mr, Boyle repeated the same experiment upon 
a plant, which at the end of two years weighed fourteen 
pounds more, and the earth in which it vegetated, lost 
no perceptible portion of its weight- 

6. Duhamel and Bonnet supported plants with moss, 
and fed them with pure water. The vegetation was of 
the most vigorous kind, and the flowers were more odo- 
riferous, and the fruit of a better flavour: Mr. Tillei 
raised plants of the gramineous kinds in- the same man- 
ner, with this difference only, his supports were of 
pounded glas«, or quartz in powder,. • 

7. Hales has observed,, that a plant that weighed 
three pounds, gained three ounces after a heavy dew. 

8. Hyacinths, and other bulbous and gTaniineous 
plants, are- sometimes raised in saucer? or bottles filled 
with water, 



o30 INTRODUCTION' 

9. Braconet caused mustard seed to germinate, grew* 
and produce plants that came to maturity, flowered and 
pipened their seed in litharge, flowers of sulphur, and 
very small unglazed shot. 

10. All plants do not require the same quantity of 
water, and nature has varied the organs of the same in- 
dividuals, agreeably to the necessity of their being sup- 
plied with this food. 

11. Plants which transpire little^ such as the mosses 
and lichens, have no need of a great quantity of water ; 
accordingly, they are placed on dry rocks, and have 
scarcely any roots ; but plants which require a larger 
quantity, have roots which extend to a great distance, 
and absorb humidity throughout their whole surface. 

12. The leaves of plants have likewise the property 
of absorbing water, and of extracting from the atmos- 
phere the same food which the root draws from the 
earth. Such are some species of aloes, and the cacti, 
which will live and flourish in dry earth for a great 
length of time, and w hen much water is added to the 
earth, they soon sicken and die. 

13. Plants which live in the water, receive the fluid 
at all their pores,and have but very little need of roots ; 
we find that the fucus, the ulva, fee. have no roots. 

1 i. The manure not only affords the alimentary 
principles, but likewise favours the growth of the plant, 
by that constant and steady heat, which its decomposition 
produces. 

13. From the above circumstances it appears, that 
ibe influence of the earth in vegetation is almost totally 
confined to the conveyance of water, and probably, the 
eiastic products, from the putrifying sul stances in the 



TO CIIEMlSTPvY. oM 

16* Vegetables cannot live without air. From the 
experiments of Priestley, Ingenhousz and Sennebier, it 
is ascertained, that plants absorb the azotic part of the 
atmosphere ; and this principle appears to be the cause 
of the fertility which arises from the use of putrefying 
matter, in the form of manure. The carbonic acid is 
likewise absorbed by vegetables, when its quantity is 
small. But in large quantities it proves fatal. 

17. According to Chaptal, the carbonic acid predom- 
inates in the fungus and other plants, when excluded 
from the light, liut by causing these vegetables, to- 
gether with the body upon which they were fixed, to 
pass, by imperceptible gradations, from an almost abso- 
lute darkness, into the light, the acid very nearly disap- 
peared ; the vegetable fibres being proportionally in- 
creased, while the resin and colouring principles were 
developed, which he ascribes to the oxygen of the same 
acid. It has been observed, that when plants are water- 
ed with water, impregnated with carbonic acid gas, they 
transpired an extraordinary quantity of oxygen, which 
likewise indicates a decomposition of the acid. 

18. Light appears to be essential to the growth of 
plants. In the dark, they grow pale, languish and die. 

Observation. The affection of plants for the light is 
manifest in such vegetation as is conducted in an apart- 
ment of the house ; where the light is admitted on one 
side, the plants all turn in that direction. If the light 
proceed from two sides, they will turn to that which is 
the strongest ; and if the light proceed from above, they 
will grow upright. In a thick wood, where but very 
little light proceeds from any direction but perpendicu- 
larly, the trees are much taller, straighter, and have 
fewer and smaller branches than those which grow in 
the open field, which is owing to the same cause. 



332 INTRODUCTION- 

19. Whether the matter of light be condensed into 
the substance of plants, or whether it act merely as a 
stimulus or agent, without which the other requisite 
chemical processes cannot be effected, is uncertain. 

20. The processes in plants serve, like those in ani- 
mals, to produce a more equable temperature, which is 
for the most part above that of the atmosphere. 

Observation. Dr. Hunter observed by keeping a ther- 
mometer plunged in a hole made in a sound tree, that it 
constantly indicated a temperature several degrees above- 
that of the atmosphere, when it was below the 5L° of 
Farenheit ; whereas the vegetable heat in hotter weath- 
er, was several degrees below that of the atmosphere. — 
The same philosopher has observed, that the sap, which 
out of the tree, would freeze at 32 a , did not freeze in 
the tree, unless the temperature was as low as n°. 

21. The vegetable heat may increase or diminish by 
several causes, of the nature of disease ; and it is saicS 
may become perceptible to the touch in very cold weath- 
er. 

22. Germination is the vital developement of a seed, 
when it first begins to grow. 

23. In order to understand the nature of germination, 
we must be acquainted with the different parts of which 
a seed is composed. 

24. The seed is formed of an external covering, cal- 
led the parenchyma, which is to constitute its first nour- 
ishment ; this imbibes nourishment from the earth, elab- 
orates it, and does not transmit it to the inclosed germec 5 
until it is reduced into proper nutriment. 

25. The seed is divided into compartments, called 
lobes or cotyledons, as is observed distinctly in the garden 
bean, which is a good example for illustration. Plate 5, 
fig. 1 and 2, A, or the dark coloured kind of string which 



Ify. /. 





Zty.3. 



Jfy. 4. 





Kenwood, 




Fitf. 7 ■ 



J&J. 



TO CHEMISTRY. 333 

divides the lobes, is called the radicle, because it forms 
the root of the plant. B. is the plumula which is enclos- 
ed within the lobes, and is that part from which the 
stem arises. At the thick end of the bean there is a 
small hole visible to the naked eve as in fig. 2 A. imme- 
diately over the radicle, in order to give it a free pas- 
sage into the soil. The plumula and the radicle in col- 
our and consistency are much alike. Fig. 7, is a trans- 
verse section of the bean. 

23. Within the radicle there is a substance called 
the seminal root, which divides into three branches ; 
the middle one runs directly up to the plumula ; the 
other two pass into the lobes on each side, and send forth 
smaller branches, till their ramifications become quite 
minute on the surface of the lobes, as in fig. 4. Fig. 5, 
is a transverse section of the radicle. Fig. 6, a trans- 
verse section of the plumula, shewing the organs or ves- 
sels of the serniiial root. 

27. When a seed is placed in a situation favorable to 
vegetation, it very soon changes its appearance. It im- 
bibes water, which softens and swells the lobes. It then 
absorbs oxygen, which imbibes some of its carbon, and is 
returned in the form of carbonic acid. This loss of car- 
bon increases the comparative proportion of hydrogen 
and oxygen in the seed, and excites the saccharine fer- 
mentation, by which the parenchymatous matter is con- 
verted into a kind of sweet emulsion. In this form, it is 
conveyed into the radicle by vessels appropriated to that 
purpose ; and in the mean time, the cotyledons are rent 
asunder, the radicle strikes into the ground, and becomes 
the root of the future plant ; hence the fermented liquid 
is conveyed to the plumula whose vessels have been 
previously distended by the heat of the fermentation.— 
The plumula being thus swelled, ajs it were, by the 



334 INTRODUCTION 

emulsive fluid raises itself up to the surface of the eartfr 
bearing with it the cotyledons, which, as soon as they 
come in contact with the air, spread themselves and are 
transformed into leaves, as in %. 3. 

28. As soon as a plant derives nourishment from the 
soil, it requires leaves, which are the organs by which 
it throws off its superabundant fluid. This transpired 
fluid consists of a little more than water* The sap, by 
this process is converted into-a fluid of a greater consis- 
tence, which is appropriated to its several. parte. 

29. When the leaves- of plants are destroyed by acci- 
dent, it not only diminishes the transpiration, but also the 
absorption by the roots. The quantity of sap absorbed 
being always in proportion to the quantity of fluid thrown 
off by transpiration. Hence it is necessary that a young 
plant should unfold its leaves as soon as it begins to derive 
nourishment from the earth. 

30. Seeds will not germinate unless moisture be present.: 
Water, therefore, appears to be essential to germination, 
too much however, is no less prejudical than none at all. 
Water is the vehicle which carries into the plant, the 
various salts and other ingredients required for the for- 
mation and support of the vegetable system. Part of the 
water itself is decomposed by the organs of the plant, 
the hydrogen becomes a constituent part of oil, of ex- 
tract, of colouring matter, &c. whilst a portion of the ox- 
ygen enters into the formation of mucilage, fecula, sugar 
and vegetable acids. But a greater part of the oxygen is 
converted into a gaseous state by the caloric disengaged 
from the hydrogen, during the condensation in the forma- 
tion of the vegetable materials. In this state the oxygen* 
is transpired by the leaves of the plant, when exposed to 
the sun's rays. 

31. Seeds will not germinate even though supplied 



TO CHEMISTRY- 335 

with a suitable portion of moisture, unless they are placed 
in a proper degree of temperature. No seed of which we 
are acquainted,will vegetate in a temperature below 32° F. 
notwithstanding a degree of cold below zero, will not des- 
troy the germinating power, unless moisture be present, 
but there must be a certain point of temperature in order 
for germination; this varies with different seeds. Every 
plant seems to require a degree of heat peculiar to itself, 
at which point its seeds begin to germinate ; for we find 
that every seed of a plant which grows spontaneously has 
a peculiar season when it springs from the earth, and 
this season varies with the temperature of the climate. 
Thus seeds of the same plant, sown at the same time in 
different countries, will germinate sooner in a warm than 
a cold one. 

32. Seeds although supplied with moisture and placed 
in a proper temperature will not germinate, provided 
atmospheric air be completely excluded from them. It is 
supposed to be owing to this circumstance, that seeds do not 
germinate when buried at great depths in the earth. Mr. 
Scheele, found that beans would not vegetate unless ox- 
ygen gas were present. No seed will germinate in pure 
nitrogen, or carbonic gas. Hence itapears that it is not 
the whole of the atmosphere, but the oxygen that causes 
the germination of seeds. 

33. It has been ascertained that seeds germinate more 
rapidly when steeped for a short time in chlorine. This 
substance is well known for the facility with which it de- 
composes water, and sets at liberty the hydrogen. 

Observation. Chlorine seems to augment the vegeta- 
tive power of seeds. Those which could not be made 
to sprout even in green houses, have been found to ger- 
minate when steeped in chlorine. By this process Mr 
Humbolt succeeded in making the seeds of many plants 



336 introduction 

which he found in South America, to grow in Vienna^ 
which not all the art of the gardeners was able,previously 
to effect. 

30. Different opinions have been entertained with 
respect to light on seeds. From experiments, it appears 
injurious, in consequence of the heat which the rajs of 
light impart to seeds, for if proper care be taken to in- 
tercept the direct rays of the sun, seeds germinate as well 
in the light as the shade. 

31. When a seed is placed in favorable situations, it 
gradually imbibes moisture, and very soon emits a quan- 
tity of carbonic acid gas, even though no oxygen be pres- 
ent in a separate state, but the process soon terminates 
and no germination takes place, but if there be a suffi- 
cient supply of oxygen gas, a portion of it is converted 
into carbonic acid gas. 

32. , From experiments it appears that if seeds be left 
to germinate in a determinate portion of oxygen gas, the 
bulk is not altered, the carbonic acid gas being equal to 
the oxygen gas which has disappeared. Hence it is in- 
ferred that the carbonic gas, contains exactly the quanti- 
ty of oxygen gas consumed. 

33. No oxygen gas is absorbed by the seed, at least 
if it be absorbed, none of it is retained, it being thrown 
off in combination with the carbon. 

34. The quantity of oxygen thus changed into car- 
bonic acid by the germination of the seed, is in some 
measure proportional to the weight of the seed. 

Observation. From the experiment of M. De Saussure, 
it appears that wheat and barle}', weight for weight, con- 
sume less oxygen than peas, while peas consume less than 
common beans and kidney beans. The oxygen consumed 
by wheat and barley amounted to 20W °* tne ^ r weight, 
while that of common beans and kidney beans, amount 
ed to ,£0 of their weight. 



TO CHEMISTRY* 337 

35. It is probable that a portion of water is forme J 
hy the union of its constituents, previously existing in 
'ha grain. 

3G. tn some plants the cotyledons do not rise above 
the earth, but in that case they perform the same office 
as those which do, that is to prepare the nourishment fer 
the sustenance of the young plant. 

37. It does not apppear that there is any communication 
between the cotyledons and the plumula, the nourishment 
therefore must pass into the plumula, from the radicle, 
accordingly, we find that the plumula does iaot begin io 
vegetate until the radicle has made some progress. But 
since the plant has ceased to vegetate, if the cotyledons 
be removed before the plumula is developed, the radi- 
cle must be sufficient of itself to carry on the process of 
vegetation, and the cotyledens are continued for the pur- 
pose of performing a part, that is, they prepare the food 
which the root at first is unable to do. 

33. When the cotyledons assume the form of leaves, 
the nourishment, which was originally deposited in them 
for the support of the embryo plant, is exhausted, but 
they still continue necessary. They must therefore re- 
ceive the nourishment which is imbibed by the root, pro- 
duce some change in it to render it suitable for the pur- 
poses of vegetation, and then send it back to be transmit- 
ted to the plumula. 

39. When the plumula has just ascended from the 
ground, if the radicle leaves be cut off, the plant does 
not cease to vegetate, but it seems to be deficient in nour- 
ishment, and scarcely ever arrives at maturity. 

40. When the plumula has arrived at a certain size, 
and completely expanded its leaves, the cotyledons may 
be removed without detriment to the plants and they very 
soon decay of themselves, It appears then that the office 

29 



$3$ INTRODUCTION 

of the cotyledon is performed by that part which is above 
ground. 

41 . The bark is composed of the epidermis, the paren- 
chyma and the cortical layes. 

42. The epidermis is the external covering of the 
plant. It is a thin transparent membrane, consisting of 
a number of slender fibres, crossing each other and form- 
ing a kind of net work. 

When of awhile glossy nature as to several species of 
trees, in the stems of rj r e and wheat and of seeds, it is 
composed of a thin coating of silicous earth, which is no 
doubt designed to protect those slender stems from in- 

Illustration. Two rattan canes struck against each 
other in the dark emit sparks of tire, 

In evergreens the epidermis is mostly resinous, and 
in some plants, it is formed of wax. This from its want 
of affinity for water, tends to preserve the plant from 
the weather, to which these species of vegetables are 
peculiarly exposed. 

43. The perenchyma is immediately beneath the epi- 
dermis, and is usually green. It is not confined to the 
stem or branches, but extends over every part of the 
plant ; it forms the green matter of the leaves, and is 
composed of tubes filled with a peculiar juice. 

44. The cortical kvyers are immediately in contact 
with the wood. They abound with tannin and gallic 
acid, and consist of small vessels through which the sap 
descends after being elaborated in the leaves. These 
layers are renewed every year. 

45. The sap ascends through the tubes of the albur- 
num or wood, which is immediately beneath the cortical 
layers. 



TO CHEJVflSTRY. 339' 

46. The wood is composed of woody fibres, mucilage 
and resin. 

The fibres are disposed of in two ways, some of them 
longitudinally, and these form what is called silver grain 
of the wood, as in fig. 8. The others, which are con- 
centric, are called the spurious grain. These last are 
disposed in layers, from the number of which the age of 
the tree may be computed, a new one being produced 
every year, by the conversion of bark into wood. The 
oldest and most internal part of the alburnum is called 
heart wood, in this no vital functions are discovered. It 
is through the tubes of the white part of the wood that 
the sap rises. These spread into the leaves, and there 
communicate with the extremities of the vessels of 
the cortical layers into which they pour their con- 
tents. 

47. The tubes of the parenchyma are supposed to 
perform the important office of secreting from the sap 
the peculiar juices from which the plant more immedi- 
ately derives its nourishment. These juices are very 
conspicuous, as the vessels which contain them are 
much larger than those through which the sap circu- 
lates. 

48. The peculiar juices of plants differ much in their 
nature, not only in different species of vegetables, but 
frequently in different parts of the same individual plant. 
They are sometimes saccharine, as in the sugar cane, 
maple, &c. sometimes resinous, as in firs and evergreens, 
and sometimes of a milky appearance, as in the 
laurel. 

49. Vegetables possess a peculiar heat, analogous to 
animal heat, and is considerably above that of unorganiz- 
ed matter in winter, and below it in summer. The wood 
of a tree is about 60° when that of the atmosphere is 



3 10 INTRODUCTION- 

about 70° or 80°. And the bark is seldom below 40 c iiv 
winter. 

50. It is from the sap after it has been elaborated by 
the leaves, that vegetables derive their nourishment ; 
in its progress through the plant from the leaves to the 
root, it deposits in several vessels with which it commu- 
nicates, the materials on which the growth and nourish- 
ment of each plant depends. It is in this way that the 
various peculiar juices are formed, such as the saccha- 
r'ne, oily, mucous, acid and colouring ; as also the more 
solid parts, fecula, woody fibre, tannin, resin, concrete 
salts. All the materials of vegetables, as well ?s the or- 
ganized parts of plants, which, besides the power of se- 
creting these from the sap for the general purpose of the. 
plant, have also that of applying them to their own par- 
ticular nourishment. 

51. The reason why plants vegetate at one season of 
the year more than at another, seems to be this. The 
warmth of spring dilates the vessels of plants and produ- 
ces a kind of vaccuum into which the sap, which had re- 
mained in a state of inaction in the trunk during winter* 
rises. This is followed by the ascent of the sap contain- 
ed in the roots, and room is thus made for fresh sap, 
which the roots in their turn pump up from the soil. 
This process goes on until the plant blossoms and bears 
fi'ult, which terminates its summer career; but when the 
cold weather sets in, the fibres and vessels contract, the 
leaves wither, and can no longer perform their office 
of transpiration, and as this secretion stops, the roots 
cease to absorb sap from the soil. If the plant be 
an annual, its life then terminates ; if not, it remains in a 
state of torpid inaction during the winter ; or the only 
internal motion which takes place, is that <?f a small quan 



TO CHEMISTRY. 341 

titj of resinous juice, which slowly rises from the stem 
into the branches, and enlarges their buds during the 
winter. 

PRACTICAL QUESTIONS. 

What is the most obvious difference between animals 
and vegetables ? 

From what does the greatest part of the support of 
animals arise ? 

What is one of the most distinguishing ^properties of 
animal substances ? 

Is ammonia exclusively confined to the animal depart- 
ment ? 

What does the nutrition of plants require ? 

Do all plants require the same quantity of water? 

What plants require the least water ? 

What property do the leaves of plants possess t 

What plants have the least need of roots ? 

What office does manure perform ? 

To what is the influence of earth, confined in vegeta- 
tion ? 

Can vegetables live without air ? 

Is carbonic acid absorbed by vegetables ? 

In what plants does the carbonic acid predom- 
inate ? 

Is light essential to the growth of plants t 

How does light act upon plants ? 

What do the processes in plants serve to produce ?"- 

How can the vegetable heat increase or dimin- 
ish? 

What is germination T 

What is necessary in order to understand the nature of 
germination ? 

Qq* 



6VZ INTRODUCTION 

What is the external covering of the seeds? 

How is the seed divided ? 

What is found within the radicle? 

What takes place at the commencement of -germina- 
tion ? 

What does a plant require when it derives nourish- 
ment from the soil ? 

What is the effect of destroying the leaves of a 
plant ? 

Is water essential to germination ? 

Is a proper degree of temperature necessary to ger- 
mination? 

Is atmospheric air necessary ? 

Has chlorine any effect on the* germination of 
seeds ? 

What effect has light on seeds ? 

What gas is emitted when seeds are placed in a favour- 
able situation ? 

Is the bulk of oxygen gas altered by germination ? 

Is any oxygen gas absorbed by the seeds ? 

What proportion does the oxygen that is changed into 
the carbonic gas bear? 

Is any water formed ? 

Do the cotyledons in all cases rise above the earth ? 

How does the plant obtain its nourishment ? 

Are the cotyledons necessary when they assume the 
form of leaves ? 

What is the effect if the radicle leaves be remov- 
ed when the plumula has just ascended from the 
ground ? 

Of what is the bark composed ? 

What is the epidermis ? 

What is the parenchyma? 

Where are the certictfl lavers situated ? 



TO CHEMISTRY 343 

How does the sap ascend? 

Of what is the wood composed ? 

Do the peculiar juices of plants differ in their na- 
ture ? 

Do vegetables have a peculiar heat ? 

From what do vegtables derive their nourishment ? 

Why do plants vegetate at one season of the year and 
not at another ? 



CHAP. XXXVI. 

Of the Animal Department. 

1. The bodies that form the subjects of chemical re- 
search have all undergone a variety of combinations and 
decompositions previously to our commencing an exami- 
nation. This process in animal matter is called animalr 
izaiion. Which is performed on substances which enter 
as nourishment into the animal system. It is performed 
by peculiar organs, and is analogous in some measure to 
the chemical process in vegetables. 

2. Animal as well as vegetable bodies, may be con- 
sidered as constituting a peculiar apparatus, for carrying 
on a determinate series of chemical operations. Vege- 
tables seem capable of operating with fluids only, and 
nearly at the temperature of the atmosphere. But most 
animals have a provision for mechanically dividing sol- 
ids by mastication ; which performs the same ofhce as 
grinding, pounding or levigating does in chemistry ; in 
this way the surfaces are enlarged to be acted upon by 
solvents. 



34 i INTRODUCTION 

3. The process carried on in the stomach, seems to be 
analogous to that which we distinguish in chemistry by 
the name of digestion. 

4. The bowels, whatever other functions they may 
perform, evidently constitute an apparatus for filtering 
or conveying off the fluids ; while the more solid parts 
of the elements which are probably incapable of being 
converted into fluids, but by an alteration which would 
perhaps destroy the texture of the machine, are rejected 
as usels-se 

Organized beings are so contrived, that their exis- 
tence continues, and all their functions are performed as 
long as the vessels are supplied with materials, to occupy 
the place of such as are carried off by evaporation, from 
the surface or otherwise ; as long as no great change is 
made, either by violence or disease, in those vessels or 
the fluids they contain. But as soon as the process is de- 
ranged in any considerable degree, the arrangements are 
altered ; the temperature in land animals is changed, the 
minute vessels are acted upon and destroyed, and this 
struck by new combinations and decompositions returns 
to the general mass of unorganized matter, with a rapidi- 
ty which is usually greater, the more complicated its con- 
struction. 

5. Animal and vegetable substances approach each 
other by insensible gradations,- so that there is scarcely 
any simple product in the one, which is not found in a 
greater or less quantity in the other. There is one prin- 
ciple however, which abounds in animals, which is rare- 
ly, and in very small quantities found in vegetables ; this 
is nitrogen. There exists likewise in animal substances 
a larger and more uniform proportion of phosphoric acid, 
and other saline matters. But these are not essential to 
animal matter 



TO CHEMISTRY. 345" 

6. Animal substances afford ammonia by destructive 
distillation ; this does not exist in the substance ready 
formed, but appears to be produced by the combination 
of hydrogen and nitrogen, during the changes produced 
either by lire or the putrefactive process. 

7. The fundamental principles of animal compounds. 
appear to be carbon, hydrogen, oxygen and nitrogen. — 
Sulphur, phosphorus, lime, magnesia and soda, are occa- 
sionally combined with these. Metals are also found in 
very minute quantities in animals. 

8. The analysis of animal substances are both difficult 
and imperfect ; for as they cannot be examined in their 
living state, and are liable to alteration immediately af- 
ter death, it is probable that when submitted to chemical 
investigation, they are always, more or less altered, in 
their combinations and properties, from what they were 
in a living state. 

9. The following are peculiar chemical products of 
animal organization, viz. Gelatine, albumen, fibrin, ca- 
seous matter, colouring matter of the blood, mucus, urea,, 
picromel, osmazome, sugar of milk, and sugar of diabetes. 
The compound animal products are the various solids 
and fluids, whether healthy or morbid, found in different 
animals, as a variety of acids, muscle, skin, bone, bloody 
urine, tears, bile, morbid concretions, brain, gastric 
juice, kc. 

10. Gelatine, or jelly is the chief ingredient of skin, 
and of all the membranous parts of animals. It may be 
obtained from these substances by means of boiling wa- 
ter, under the forms of glue, size, isinglass, and transpar- 
ent jelly, 

11. It is soluble in water, and is capable of assuming 
a well known elastic, and tremulous substance by cool- 
ing, when the water is not too abundant, and liquifiable 



M6 HTTRODLCTTON 

again on increasing its temperature. This last property 
distinguishes it from albumen, which becomes consistent 
by heat. It is precipitated in an insoluble form by tan- 
nin, and it is this action of tannin on gelatine that is the 
art of tanning leather. In its solid state, it is a semi- 
transparent substance, without taste or smelL 

12. Leather can be produced only from gelatine in a 
membraneous state, the texture of the skin being neces- 
sary to the purposes of leather, 

13. Glue is extracted from the skin of animals. 

14. Size is obtained either from skin in its natnral 
state, or from leather. 

15. Isinglass is gelatine procured from a species of 
fish called the sturgeon, and is called Ichthyocolla. 

16. Gelatine may be obtained from almost any ani- 
mal substance. Bones produce it in considerable quan- 
tities, as they consist of phosphate of lime, cemented by 
gelatine. Horns yield abundance of gelatine. 

17. It is from the gelatine of bones that ammonia is 
produced. By the simple action of water and heat, the 
gelatine is separated ; and to procure the ammonia, the 
bones are distilled, by which means, the gelatine is de- 
composed, and the hydrogen and nitrogen combine in the 
form of ammonia. The first is a mechanical separation 
of the ingredients, but the latter, a chemical decomposi- 
tion. 

18. Gelatine may be precipitated from its solution in 
water by alcohol. The alcohol combining with the wa- 
ter, while the gelatine is set at liberty. 

Exp. Take a glass of warm jelly, and add a few 
drops of alcohol, the gelatine falls down in an. insoluble 
mass 



TO CHEMISTRV. 349 



19. Gelatine is composed of 

Carbon, 47.881 
Oxygen, 27.207 
Hydrogen, 7.914 
Nitrogen, 16.998 



100.000 

20. Albumen derives its name from the latin, and sig- 
nifies the white of an egg^ in which it exists abundantly, 
and in its purest natural state is one of the principal con- 
stituents of all animal solids. It abounds in the serum of 
blood, the vitreous and crystalline humours of the eye, 
und the fluid of dropsy. 

21. It is coagulable by heat. It is soluble in cold 
Water, previously to coagulation, but not afterwards. — 
Pure alkalies dissolve it, even after coagulation. It is 
precipitated by muriate of mercury, nitro muriate of tin, 
acetate of lead, nitrate of silver, muriate of gold, infusion 
of galls and tannin. The acids and metallic oxides co- 
agulate albumen. 

22. Solid albumen may be obtained by agitating 
white of egg with ten or twelve times its weight of al- 
cohol. This seizes the water which held the albumen 
in solution, and this substance is precipitated under the 
ibrm of white flocks or filaments, which are rendered 
insoluble by cohesive attraction. 

23. Albumen thus obtained is like fibrine, solid, 
white, insipid, inodorous, denser than water, and without 
action on vegetable colours. It dissolves in potash and 
soda more easily than fibrine, and more difficult in acetic 
acid 

24. 100 parts of pure albumen consist of 

Carbon, 52.883 

Oxygen, 23.872 



S 1 £ Ik troductios 

Hydrogen, 7.540 
Nitrogen, 15.705 



100.000 

25. Fibrine is another animal substance ; it is found 
also in vegetables:. It is a soft solid, of a greasy appear- 
ance, insoluble in water, softens in the air, and becomes 
viscid, brown and semi-transparent. On hot coals it 
melts, throws out greasy drops, crackles, and evolves the 
smoke and odour of roasting meat. It exists in chyle, it 
enters into the composition of blood ; it forms the prin- 
cipal part of muscular flesh, and may be regarded as the 
most abundant constituent of the soft solids of animals. 

26. It may be obtained by beating blood as it issues 
from the veins, with a bunch of twigs. Fitrine soon at- 
taches itself to the twigs, under the form of long reddish 
iilaments, which become colourless by washing them 
with cold water. 

27. It is solid, white, insipid, without smell, denser 
than water, does not change the infusion of litmus or vio- 
lets. When moist, it possesses a species of elasticity. — - 
It becomes yellowish, hard and brittle, by drying. 

28. It is composed of 

Carbon, 53.360 
Nitrogen, 19.934 
Oxygen, 19.6S5 
Hydrogen, 7.021 



100.000 
29. Caseous matter is a substance procured from milk. 
Cheese is obtained from milk by means of rennet, which 
is a watery infusion of the coats of the stomach of a suck- 
ing calf. It possesses the property of coagulating milk, 
which is supposed to be owing to the gastric juice with 



TO CHEMISTRY. 349 

•which it is impregnated. What remains after the sepa- 
ration of the curds is called whey, from which may be 
obtained a substance, by evaporation, called sugar of 
milk. This substance is sweet to the taste, and is sus- 
ceptible of undergoing the vinous fermentation. Whey, 
by combining with oxygen, is capable of being acidified 
^md of forming the lactic acid. 

30. The nature and flavour of cheese depend on the 
cream or oily matter, and likewise, it is said, on a pecu- 
liar acid, called caseic acid. If both these substances be 
removed from the cheese, it becomes insipid and totally 
tmfit for food, 

31. Colouring matter of blood is a peculiar compound ; 
it does not exist in any other organized body. To ob- 
tain it pure, mix blood with 4 parts of sulphuric acid, 
previously diluted with 8 parts of water, and expose the 
mixture to a heat of about 160® for 5 or 6 hours, filter 
the liquid while hot, and w&sh the residue with a few 
ounces of hot wateT. Evaporate the liquid to one half t 
and add ammonia, till the acid be almost but not entirely 
saturated. The colouring matter falls. Decant the su- 
pernatant liquid, filter and wash the residuum from the 
ammonia. When it is well drained, dry it in a cap- 
sule. 

32. When solid, it appears of a black colour, but be- 
comes wine red by diffusion through water ; in which, 
however, it is not soluble. It is destitute of taste and 
smell. It is soluble both in alkalies and acids. It ap- 
proaches to fibrine in its constitution, and contains iron 
in a peculiar state. One third per cent of the oxide may 
be obtained by calcination, according to Dr. Ure. The 
incinerated colouring matter weighs 1 -80th of the whole, 
and the ashes consist of 50 oxide of iron, 7.5 sub-phos- 
30 



350 



L\ rRODUCTIOS 



phate of iron, 6 phosphate of lime with traces of mag- 
nesia, 20 pure lime, 16.5 carbonic acid. 

Observation. Berzelius thinks that none of these bod- 
ies existed in the blood, but only their bases, iron, phos- 
phorus^ calcium, carbon, &c, and that they were formed 
during the incineration. 

33. The buff y coat of inflamed blood is fihrine, from 
which the colouring matter has been precipitated, from 
the greater liquidity or slowness of coagulation during 
the disease. 

34. Mucus is one of the primary animal fluids, per- 
fectly distinct from gelatine. The subacetate of lead 
does not affect gelatine -; on the other hand, tannin, 
which is a delicate test of gelatine, does not affect mucus. 
Both these reagents, however, precipitate albumen ; 
but the oxymuriate of mercury, which will indicate the 
presence of albumen dissolved in 2000 parts of water, 
precipitates neither mucus nor gelatine. Thus we have 
three distinct and delicate tests for these three different 
principles. 

35. Urea is an animal substance, prepared from urine. 
It crj'stallizes in four sided prisms, which are transparent 
and colourless, with a slight pearly lustre. It has a pe- 
culiar, but not urinous odour. It does not affect litmus 
or tumeric papers, fit is permanent in the atmosphere. 
In damp weather it deliquesces slightly. In a strong- 
heat it melts, and is partly decomposed and partly sublim- 
ed without change. The specific gravity of the crystals 
is about 1.35. It is very soluble in water. Alcohol at 
the temperature of the atmosphere, dissolves about 20 
per cent ; when boiling, considerably more than its own 
weight. It is decomposed by fixed alkalies and alkaline 
earths. It unites with most of the metallic oxides, and 



TO CHEMISTRY, 35 b 

forms crystalline compounds with the nitric and oxalic 
acids. 

36. Urea is composed, according to Dr. Prout, of 

Hydrogen, 10.80 

Carbon, 19.40 

Oxygen, 26.40 

Nitrogen, 43.40 



100.00 

37. Picromel is the characteristic principle of bile. — 
It resembles inspissated bile, ^ Colour greenish yellow. 
Taste intensely bitter at first, which is succeeded by an 
impression of sweetness. It is not affected by an infu- 
sion of galls. The salts of iron and subacetate of lead 
precipitate it from its aqueous solution. By destructive 
distillation it affords no ammonia ; hence nitrogen apr 
pears not to be a •■constituent part of this substance. 

38.-. Osmazmne is a peculiar substance,. extracted from 
the brain of animals. It is a soft solid brownish yellow 
substance, of a greasey glutinous feel, and of a brilliant 
appearance, like satin. It melts on exposure to heat, 
though it does not become softened like tallow. Its 
aqueous solutions afford precipitates, with infusion of 
galls, nitrate of mercury, and nitrate and acetate of 
lead. 

34. Sugar of milk is a substance obtained from the 
whey of milk. 

40. It is soluble in five parts of cold, and two and 
a half of boiling water. It is white, of a sweetish taste, 
and inodorous. It is insoluble in alcohol and ether ; by 
the addition of a small quantity of sulphuric acid, it may 
be dissolved in alcohol. It is soluble in acetic and muri- 
atic acids, and absorbs muriatic acid gas, forming a grey 
powder. It is decomposed by chlorine and solution of 



352 MTRODfrCTION 

caustic potash. By nitric acid it is converted into sac 
lactic acid. It is decomposed by heat and affords a resi- 
duum of charcoal., 

41. According to Berzelius, it consists of 

Carbon, 45.267 

Oxygen, 48.348 

Hydrogen, 6.385 



100.000 

42. Sugar of diabetes is a substance obtained from the 
urine of diabetic persons. It may be procured by pour- 
ing into the urine a solution of Goulard 9 s extract of lead, 
filtering and evaporating the liquid to the consistence of 
syrup. After some time, it precipitates. The propor- 
tions of urine vary at different times from 1-30 to 1-17 
of the whole weight. The disease is supposed to be 
©wing, in some measure, to vegetable diet. When heat- 
ed with nitric acid, it yielded the same proportion of 
oxalic acid as an equal quantity of common sugar would 
have done, allowing for the saline substance present. — 
From experiment, it appears that this substance is not 
analogous to sugar of milk, but nearer common sugar ia 
its properties. It crystallizes in a similar manner as su- 
gar of grapes. 

43. The beautiful pigment, called Prussian blue, is ob- 
tained commonly from animal matters, such as blood, 
horns, hoofs, skin, hair, wool, &c. ; but it may be formed 
without the presence of any animal matter, and may 
likewise be obtained from a variety of vegetables. — 
When formed from animal substances, they are first 
charred, then mixed with potash, and the mixture cal- 
cined in a covered crucible, the alkali attracts the acid 
from the coal, and forms with it a prussiate of potash, 
which being mixed in solution with sulphate of iron, for 



TO CHEMISTRY. 353 

which the prussic acid has a greater affinity than for the 
alkali, produces the Prussian hlue. 

44. The muscles consist of bundles of fibres which 
terminate in a kind of string or ligament, by which they 
are fastened to the bones. They are the organs of mo- 
tion ; by their power of dilatation and contraction they 
put into action the bones, which act as levers in all the 
motions of the body, and form the solid support of its 
various parts. 

45. The muscles are of various degrees of strength 
or consistence, in different species of animals. The 
mammiferous tribe seem, in this respect, to occupy an 
intermediate place between birds and cold blooded ani- 
mals v such as reptiles and fishes. 

46. The muscles of different animals differ very muck 
in their appearance and properties ; at least, as articles 
of food. According to Thouvenal, the flesh of the ox 
contains the greatest quantity of insoluble matter, . and 
leaves the greatest residuum when dried; the flesh of 
the calf is more aqueous and mucous ; the land and water 
turtle yields more matter to water, than the muscle of 
the ox ; snails yield to. water a quantity of matter inter- 
mediate between that given by beef and veal ; the mus- 
cles - of frogs, xray fish, ..and vipers, agree nearly with 
snails, in their yielding a quantity of matter- to water ; 
but the muscles of fresh water fish, yield a considerably 
smaller proportion.- 

47. When meat is boiled, the gelatine r the extrac- 
tive, and a portion of the salts will be separated, while 
the coagulated albumen and fibrine will remain in a solid 
state ; hence the flavour and nourishing nature of soups, 
which is -derived from the extractive and gelatine. 

48. The flavour of roasted meat is owing to the 
presence of the eelatine, extractive matter, and salts. 

30* ~ 



354 INTRODUCTION 

49. The skin is that strong thick covering which en- 
velopes the whole external surface of animals. It is 
formed of two parts, a thin white elastic layer on the 
outside, called epidermis, or cuticle ; and a much thicker 
layer, composed of a great many fibres, closely inter- 
woven, and disposed in different directions, called the 
Cutis, or true skin. 

Note. — The epidermis is that part of the skin which is 
raised in blisters. 

50. The cuticle is transparent, as well as porous, 
through which the mucous membrane, or true skin is 
seen, which in the European and American is white or 
brown, and in the negro, black. 

51. The extremities of the nerves are spread over 
the true skin, so that the sensation of feeling is trans- 
mitted through the cuticle. 

52. The cutis, or true skin, appears to be a peculiar 
modification of gelatine, calculated to resist the action of 
water, partly by the compactness of its texture, and part- 
ly by the viscidity of the gelatine. 

53. It is from the skin or cutis, that leather is form- 
ed ; and the goodness of leather, or at least its strength 
depends, in some measure, on the roughness of the hides.. 
Those easily soluble, as seal skins, afford a weaker leath- 
er than those which are more difficultly soluble in water. 
The process by which the skins of animals are converted 
into leather, is called tanning. 

54. The cavities between the muscles and skin are 
usually filled with fat, which lodges in the cells, and im- 
parts to the external form, in the human figure, that, 
roundness, smoothness and softness, which is so attractive, 
ornamental and beautiful. 

55. Bene is the solid, well known substance which 
gives firmness arc strength to animal bodies. The tex- 



TO CHEMISTRY. 355 

ture of bone is sometimes dense, at other times cellular 
and porous, according to the situation. 

56. Bones consist of phosphate of lime, cemented by 
gelatine, to which it owes its great firmness and solidi- 
ty 

57. Calcined human bones, according to Berzehus, 

are composed, in 100 parts, of 

Phosphate of lime, 81.9 
Fluate of lime, 3 

Lime, 10 
Phosphate of magnesia, 1.1 
Soda, 2 

Carbonic acid, 2 



100.0 
58. Fourcroy and Vauquelin found the following to be 
the composition of 100 parts of ox bones. 
Solid gelatine, 51 

Phosphate of lime, 37.7 

Carbonate of lime, 10 

Phosphate of magnesia, 1.3 

100.0 
According to Rerzelfus, they are composed, as follows,. 
Cartilage, 33.3 

Phosphate of lime, 55.35 
Fluate of lime, 3 

Carbonate of lime, 3.85 

- ^Phosphate of magnesia, 2.05 
Soda, 2.45 



100.00 
59. The earthy salts are retained in their respective 
places, or interstices, by a membranous or cartilaginous 
substance, which is found to be indurated albumen. 



356 INTRODUCTION 

60. The bones of animals acquire a red tinge, in con- 
sequence of taking madder with their food. The bones 
of young pigeons will thus be tinged, of a rose colour, in 
twenty-four hours, and of a deep scarlet, in three days. 
The bones most remote from the heart are the longest 
in acquring this tinge. 

61. Bones are of extensive use in the arts. In their 
natural state, or dyed of various colours, they are made 
into handles of knives and forks, and numerous other ar- 
ticles. The} r are also used for the preparation of the 
volatile alkali, or ammonia, and for making of jelly. 

62. Blood is the fluid which first presents itself to 
observation, when the parts of living animals are divid- 
ed or destroyed, and which circulates through the veins 
and the arteries to every part of the body. 

33. Recent blood is uniformly fluid, and of a saline 
taste. Under the microscope, it appears to be compos- 
ed of a great number of red globules swimming ia a 
transparent fluid. After standing for a short time, its 
parts separate into a thick red matter, or crassamenturru 
and a fluid, called serum. 

64. Blood usually consists of about 3 parts serum to 1 
of cruor. 

65. The serum is cf a pale greenish yellow colour. 
Its specific gravity is about 1.029, white that of blood it- 
self is 1.053.. It changes syrup of violets to a green, 
from its containing free soda. At 156° serum coagulates 
and resembles boiled white of egg. When this coagu- 
lated albumen is squeezed, a muddy fluicf exudes, which 
has been called the serosity, 



TO CHEMISTRY. ^5T 



• 66. According to Berzelius, 1000 parts of the serum 


of bullock's blood consist of 




Water 


905 


Albumen 


79.99 


Lactate of soda and extractive matter 


6.175 


Muriate of soda and potash 


2.565 


Soda and animal matter 


1.52' 


Loss 


4.75 



1.000 
1000 parts of serum of human blood consist of 
Water 905 

Albumen 80 

Muriate of potas and soda 6 

Lactate of soda with animal matter 4 

Soda, phosphate of soda with animal matter 4.1 
Loss 9 



,: 1000.0 

67. There is no gelatine in serum. 

68. The cruor has a specific gravity of 1.245. By 
making a stream of water flow upon it, till the water runs 
offcolourless,itis separated into insoluble fibrine, and the 
soluble colouring matter. A little albumen has likewise 
been found in cruor. The proportions of the former 
two are 64 colouring matter and 36 fibrine in 100. 

69. Urine, in its natural state, is transparent, of a 
yellow colour, a peculiar smell and saline taste Its pro- 
duction as to quantity, and in some measure quality, de- 
pends on the seasons, and the peculiar constitution of the 
individual, and is likewise modified by disease. It is ob- 
served that prespiration carries off, more or less of the 
fluid of the body which would otherwise have passed off 



358 INTRODUCTION 

by urine ; so that a profusion of the former^ is attended by, 
a diminution of the latter. 

70. Urine is composed of the following parts. 
Water 1 
Urea 2 
Phosphoric acid 3 
Phosphate of lime 4 

of magnesia 5 

of soda 6 

of ammonia 7 

Lithic acid 8 

Rosacic acid 9 

Benzoic acid 10 

Carbonic acid 11 

Carbonate of lime 12 

Muriate of soda m 13 

of ammonia 14 

Gelatine 15 

Albumen 16 

Resin 17 

Sulphur 18 

71. The urine undergoes considerable changes by dis- 
eases, a knowledge of which is of importance. In inflam- 
matory diseases it is of a red colour, small in quantity 
and peculiarly acrid, but deposits no sediment on stand- 
ing. Corrosive muriate of mercury throws down from it a 
copious precipitate ; towards the termination of the dis- 
ease, it becomes more abundant, and deposits a copious 
piak coloured sediment consisting of rosacic acid, with 
a little phosphate of lime and uric acid. 

72. In jaundice the urine is of a deep yellow colour, 
capable of staining linen. Muriatic acid renders it green, 
and this indicates the presence of bile. 



IPO CHEMISTRY; 35i) 

v /3. In hysterical affections it is copious, limpid and 
colourless, containing much salt, but scarcely any urea or 
gelatine. 

74. In dropsy the urine is generally loaded with albu- 
men, -so as to become milky, or even to coagulate by 
heat, or on the addition of acids. 

75. In dropsy from diseased liver no albumen is pres- 
ent, but the urine is scanty high coloured, and deposits 
the pink coloured sediment. 

76. In dyspepsy or indigestion, the urine abounds in 
gelatine, and putrefies rapidly. 

77. In rickets (he urine contains a great quantity of 
calcareous salt, which is found to be the oxalate of 
4ime. 

78. In diabetic patients, the urine is sometimes so 
loaded with sugar as to be capable of being fermented 
into a vinous liquor. Sometimes, however, the urine is 
not sweet, but insipid. 

79. Urine has been employed for making phospho- 
rus, volatile alkali and sal-ammoniac. It is used in a pu- 
trid state for scouring woolens. 

80. Tears compose that peculiar fluid which is ap- 
propriated to lubricating the eye, and which is emitted in 
considerable quantities when we express grief by weep- 
ing. 

81. This liquid is transparent and colourless like wa- 
ter ; it has scarcely any smell, but its taste is always per- 
ceptibly salt. Its specific gravity is somewhat greater 
than that of distilled water. It gives to paper stained 
•with the juice of violets, a permanently green colour^ 
hence we infer the presence of a fixed alkali. It Unites 
with water, whether cold or hot, in all proportions. Al- 
kalies unite with it readily and render it more fluid. The 
mineral acids produce no apparent change upon it. Ex- 



360 INTRODUCTION • 

posed to the air, it gradually' evaporates and becofnes 
^hick. 

82^ Tears are composed of 1 Water, 

2 Mucus, 

3 Muriate of soda, 

4 Soda. 

5 Phosphate of lime, 

6 Phosphate of soda. 
The saline parts of tears amount only to about 0.01 of 

ihe whole. 

83. Bile is a bitter liquid of a yellowish or greenish 
yellow colour, more or less viscid. Specific gravity 
greater than that of water, common to & great number 
of animals, the peculiar secretion of their liver. It is 
the prevailing opinion of physiologists, that the bile is 
separated from tho venous, and not from the arterial 
blood. The veins which receive the blood distributed to 
the abdominal viscera, unite into a large trunk called the 
vena porta, which divides into two branches, that pene- 
trate into the liver, and divide into innumerable ramifica- 
tions. The last of these terminate partly in the biliary ducts, 
and partly in the hepatic veins, which restore to the cir- 
culation that portion of blood which is not necessary for 
the formation of bile. This liquid passes directly into the 
duodenum, when the animal has no gall-bladder ; but 
when it has one, as more frequently happens, the bile 
flows back into it by the cistic duct, and remaining there 
for a longer or shorter time, experiences remarkable aU 
terations. Its principal use seems to be, in promoting 
digestion, in concert with pancreatic juice. 

81. Ox bile is usually of a greenish yellow colour, 
rarely deep green. It is at once very bitter and slight* 
%j sweet. Its taste is scarcely supportable. Its smeIl T 



TO CHEMISTRY. ->bl 

though feeble, is easily recognizable, and approaches 
somewhat to the nauseous odour of some fatty matters 
when they are heated. 

Its specific gravity is about 1.026 at 43° F. 
Ox bile is composed of 

Water 7.00 

Resinous matter 05 

Picromel 69.00 

Yellow matter 4.00 

Soda 4.00 

Phosphate of soda 2.00 

Muriate of soda 3.5 

Sulphate of soda 0.8 

Phosphate of lime 1 2 

Oxide of iron a trace 

93.0 

86. Brain is a soft pulpy substance, with little or no 
smell. Exposed to a gentle heat, moisture evaporates, 
it shrinks to about a fourth of its original bulk, and be- 
comes a tenacious mass of a greenish brown colour ; 
when completely dried, it becomes solid and friable 
like old cheese. In its natural state, or moderately dried, 
it readily forms an emulsion by trituration with water 
and is not separated by filtration* This solution lathers 
like soap suds, but does not turn blue vegetable infusions 
green. 

87. Its constituents, according to Vauquelin, are, in 
100 parts, 

Water 80 

White fatty matter 4.53 

Reddish fatty do. 0.7 

Albumen 7.0 

Osmazome 1,1 £ 
31 



362 INTRODUCTION 

Phosphorus IS 

Acids, salts and sulphur 5.15 



100.00 
88. The medulla oblongata and nerves have the same 
chemical composition as the brain. 

39. Gastric Juice is separated by glands placed be- 
tween the membranes which line the stomach ; and from 
these it is emitted into the stomach itself. It reduces the 
aliment into a uniform mass, even when out of the body. 
It acts in the same manner on the stomach after death ; 
which proves that the action is chemical, and not depen- 
dent on vitality. 

90. The gastric juice affects the solution of aliments 
included in tubes of metal, consequently defended from 
any trituration. 

91. Though there is no trituration in membraneous 
stomachs, this action powerfully assists the effect of the 
digestive powers in animals with muscular ones, such as 
fowls. 

92. The gastric juice acts by its solvent power, and 
not as a ferment This appears evident from there not 
being any disengagement of air in ordinary digestion ; 
neither is there any inflation, or increase of heat, nor 
any other of the ordinary phenomena of fermentation. 

PRACTICAL QUESTIONS. 

What is animalization ? 

How may animals as well as vegetables be consid- 
ered ? 

Can the animal process be compared with that of the 
chemical ? 

To what do you compare the process in the stom- 
ach ? 



TO CHEMISTRY. 303 

What kind of apparatus do the bowels constitute ? 

How are organized bodies contrived ? 

Do animals agree with vegetables in their composi- 
tion ? 

What do animal substances afford by distillation ? 

What are the fundamental principles of animal com- 
pounds ? 

From what cause arises the difficulty of analizing ani- 
mal substances ? 

What are the peculiar products of animal organiza- 
tion ? 

What is gelatine ? 

What are its properties? 

From what is leather produced ? 

From what is glue obtained I 

From what size ? 

What is isinglass ? 

From what can gelatine be obtained ? 

From what is ammonia obtained ? 

How can gelatine be separated from its solution i 

Of what is gelatine composed ? 

What is albumen ? 

What are its properties T 

How can solid albumen be obtained? 

What are the properties of solid albumen ? 

What is fibrine ?. 

How can it be obtained ? 

What are its peculiar properties? 

Of what is it composed ? 

What is caseous matter ? 

On what does the nature and flavour of cheese de- 
pend ? 

How do you obtain the colouring matter of blood ? 

What are its characteristics ? 



364 INTRODUCTION 

What is the buffy coat of inflamed blood ? 

How do you distinguish mucus from gelatine and albu- 
men ? 

What is Urea ; and what are its properties ? 

Of what is it composed ? 

What is Picromel ? 

What is osmazome ? 

What are its properties ? 

What is sugar of milk ? 

Of what does it consist? 

What is sugar of diabetes ? 

From what is prussian blue obtained 1 

Of what do muscles consist ? 

Whence does roasted meat derive its flavor ? 

Of what is skin formed ? 

How is the sensation of feeling transmitted through 
the cuticle ? 

With what are the cavities between the muscles and 
the skin filled ? 

What is bone ? 

To what do bones owe their great firmness and solid* 
ity ? 

Of what are calcined human bones composed ? 

Of what do ox-bones consist ? 

Of what is that composed which appears to retain the 
earthy salts in their places ? 

What is the consequence of giving madder to animal* 
in their food ? 

Are bones of any use in the arts ? 

What is blood ? 

What appearance has recent blood ? 

Of what does blood consist ? 

What are the properties of serum ? 

Of what does it consist ? 



TO CHEMISTRY 66 5 

What is said of cruor ? 

What are the properties of urine ? 

Of what is it composed ? 

Does urine undergo any change by disease ? 

How is it in jaundice ? 

How in hysterical affections? 

How in dropsy ? 

How in dyspepsia ?' 

How in rickets ? 

How in diabetic patients ? 

Is urine employed in the arts ? 

W r hat are the properties of tears ? 

Of what are tears composed ? 

What are the properties of bile ? 

What are the properties of ox-bile? 

Of what is it composed ? 

What is brain ? 

Of what is it composed? 

Wliat is the gastric juice and its office ? 

Does the gastric juice act by its solvent powers or by 
trituration ? 

How do you prove that this action is not by fermenta- 
tion ? 



CHAP. XXXVII. 

Of Respiration. 
1. Respiration is a function in animals which consists 
m the alternate inhalation of a portion of air into an or- 
gan called the lungs, and its subsequent exhalation. 
31* 



366 INTRODUCTION 

2. In order to form any determinate opinion of the 
phenomena of respiration, there are two things to be 
considered in the first place, viz. the mechanical and the 
chemical part of the process. 

3. The mechanism of breathing- depends on the al- 
ternate expansions and contractions of the chest. When 
the chest dilates, the cavity enlarges, and the air rushes 
in at the mouth,to fill up the vacuum formed by this dila- 
tation, when it contracts, the cavity is diminished and the 
air again forced out. 

4. The lungs likewise contract and expand inbreath- 
ing, in consequence of that of the chest. The lungs, to- 
gether with the breast and largest blood vessels, in a man- 
ner fill up the cavity of the chest ; it must therefore pre- 
viously expand in order for the dilatation of these organs. 
When it contracts, it presses on the lungs and forces the 
air out of them, in a manner similar to bellows. 

5. The chest is a large cavity in the upper part of the 
body, contained within the ribs, the neck and the dia- 
phragm. 

6. The diaphragm is that membrane which separates 
the chest from the lower part of the body, which is mus- 
cular and capable of great dilatation and contraction. 
When this contracts the space within the chest is dimin- 
ished, and of course the air is pressed out from the lungs^ 
On the other hand, when the membrane dilates, the cav- 
ity is enlarged, and the external air rushes in to keep 
up the equilibrium, so that as long as this action of the 
diaphragm continues, respiration is carried on. 

7. Besides the motion of the diaphragm, there is also 
a muscular motion of the ribs, which contribute towards 
enlarging or diminishing the cavity of the chest. These 
are alternately drawn edgewise to assist the contraction, 



TO CHEMISTRY. 367 

and stretched out like hoops of a barrel, to contribute 
to the dilatation of the chest. 

8. These two muscular contractions, viz. of the dia- 
phragm and the ribs, are to be considered as the causes 
of the contraction and expansion of the chest ; and the 
air rushing into and being expelled from the lungs, is 
only the effects of those actions. 

Illustration. Open the mouth without any action of 
the chest, the air will not rush in until by an interior 
muscular action, a vacuum be produced. 

9. In general, this alternate action of dilatation and 
contraction, in a healthy person, is between fifteen and 
twenty times in a minute. 

10. Previously to our proceeding to the chemical 
effects of respiration, it is necessary that we should un- 
derstand the theory of the circulation of the blood. 

11. In the system there are tw T o kinds of blood ves- 
sels, the veins and arteries, each possessed of peculiar 
functions. 

12. The arteries convey the blood from the heart to 
the extremities of the body ; and the veins bring it back 
to the heart. 

13. The heart is a muscular cavity, which possesses 
a power of dilating and contracting itself, for the purpose 
of alternately receiving and expelling the blood, in order 
to carry on the process of circulation. 

14. The blood in the arteries is of a beautiful red 
colour, but when it passes into the veins it becomes pur- 
ple. This change depends upon various circumstances. 
In the first place, the blood, during its passage through 
the arteries undergoes a considerable alterations-some of 
its constituent parts are gradually separated from it, for 
the purpose of nourishing the body, and of supplying the 
various secretions, Consequently, the florid arterial col- 



368 INTRODUCTION 

our of the blood changes by degrees to a deep pnrpley 
which is its constant colour in the veins. During the 
return of the blood through the veins, it is renewed by 
fresh chyle or imperfect blood, which has been produc- 
ed by food. It receives also lymph from the absorbent 
vessels. In consequence of these several changes, the 
blood returns to the heart in a state different from that 
in which it left it. It is charged with a greater propor- 
tion of hydrogen and carbon, and is no longer fit for the 
nourishment of the body, or other purposes of circula- 
tion. 

15. The heart is divided into two cavities, called the 
right and left ventricles. The left ventricle is the re- 
ceptacle for the pure arterial blood, previously to its 
circulation; whilst the venous or impure blood, which 
returns to the heart, after having circulated, is received 
into the right ventricle, previously to its purification. 

16. As the blood conveys nourishment to the body in 
the course of circulation, there must be some process by 
which it can be supplied with the means of imparting 
this nourishment ; this is by respiration, or the chemical 
part of it. 

17. When the venous blood enters the right ventri- 
cle of the heart, this organ contracts by its muscular 
power and throws the blood through a large vessel, cal- 
led the puh no nary artery, into the lungs, which are con- 
tiguous, and through which it circulates by innumerable 
small branches. It is here brought in contact with the 
air which we breathe. 

18. The venous blood which enters the lungs from 
the pulmonary artery, is charged with carbon, to which 
it owes its dark purple colour. When the oxygen of the 
atmosphere is applied to the interior of the air vesicles of 
the lungs, it combines with the carbon of the blood, 



TO CHEMISTRY. 56 9" 

forms carbonic acid; which, to the amount of from 4.5 to 
8 per cent of the bulk of the air inspired is immediately 
exhaled. 

19. It does not appear that any oxygen or nitrogen, 
the two constituents of the atmosphere, are absorbed by 
the lungs during respiration ; for the volume of carbonic 
acid generated, is exactly equal to that of the oxygen 
which disappears ; now we know that carbonic acid 
contains its own volume of oxygen. 

20. The change of the blood from the purple venous 
to the bright red arterial, seems owing to the discharge 
of the carbon, with which it is impregnated during the 
circulation, in consequence of its affinity for oxygen. 

21. An ordinary sized maa> in health, consumes about 
forty-six thousand cubic inches of oxygen in a day, which 
is equal to one hundred and twenty-five cubic feet of 
atmospheric air. The sam§' quantity of carbonic acid is 
expelled. 

22. About twenty respirations are made in a minute^ 
or, a man breathes twice for every seven pulsations, 

23. It has been found that after swallowing intoxicat- 
ing liquors, the quantity of carbonic acid formed in res- 
piration was diminished. The same thing is said to hap- 
pen under a course of mercury, nitric acid, or vegetable 
diet. 

24. Carbon appears to exist in a greater proportion 
in blood, than in any other organized animal matter. — - 
By this means, the blood, after supplying its various se- 
cretions, becomes loaded with an excess of carbon, which 
is carried off by respiration ; and the formation of new 
chyle from the food, affords a constant supply of carbo- 
naceous matter, 



3:10 ECTRODIXTION. 

PRACTICAL QUESTIONS. 

What is respiration ? 

What is necessary in order to form a correct opinion 
of respiration ? 

On what does the mechanism of breathing depend ? 

Is the expansion and contraction of the chest in conse*. 
quence of that of the lungs ?. 

What is the chest 7 

W T hat is the diaphragm ? 

W r hat office does it perform ? 

W T hat office do the ribs perform ?' 

How are these muscular contractions of the diaphragm 
and ribs to be considered ? 

How do you illustrate this ? 

How often is this alternate dilatation and contraction r i 

How"mr\$T &inds of blood, vessels are there ? 

What are their offices ?. 

What is the heart ?. 

How is the blood in the veins and arteries, what are 
the changes produced, and the causes of those changes? 

How is the heart divided ? 

What is the process by which the blood can be sup- 
plied with the means of affording nourishment to the 
system ? 

How is the blood brought in contact with the air 
which we breathe ? 

To what does the blood owe its purple colour ? 

Is oxygen or nitrogen absorbed by the lungs ? 

To what is the change of the blood from the purple 
to the red arterial owing ? 

How much oxygen do we consume in a day ? 

How many respirations are made in a minute ? 



TO CHEMISTRY* 371 

How is the quantity of carbonic acid diminished in 
respiration ? 

How is it that the blood acquires such a quantity of 
carbon ? 



CHAP. XXXVIII. 

On Animal Heat, &c. 

1. During respiration, heat is disengaged. It has 
been calculated that the heat produced by respiration 
in twelve hours, in the lungs of a person in health, is 
such, as would melt about one hundred pounds of ice. 

2. Venous blood has been found by experiment to 
have less capacity for heat than arterial blood ; and the 
blood in passing from the arterial to the venous state 
during circulation, parts with a portion of caloric, by 
means of which, heat is diffused through every part of 
the body, 

3. The heat of animals is various, according to the 
variety of species of animals, the differepxe of seasons 
and climates, and the state of the same animal, at differ- 
ent periods. 

4. Animals have been very properly divided into hot 
and cold blooded animals ; reckoning those to be hot 
which are near our own temperature ; and all others 
cold, whose heat is much below ours, or which give us 
the sensation of cold ; such as most insects. Though 
the heat of a swarm of bees raised a thermometer to 
97°, indicating a degree of heat but little, if any inferior 
to our own. To this class, belong muscles and oysters, 
snails, frogs, serpents, &e; 



372 INTRODUCTION 

5. The human kind forms the lowest gradation in the 
'class of hot animals ; the mean heat of the human body 
as deduced from a variety of experiments, is about 97°. 

6. With respect to quadrupeds, the heat of their bodies 
will raise the thermometer three or four degrees higher 
than those of the human kind ; and the bodies of birds 
are still warmer, 

7. It appears from a variety of experiments and ob- 
servations^ that those animals which are furnished with 
lungs, and which continually receive the fresh air in 
great quantities, have a power of keeping themselves at 
a temperature considerably higher than the surrounding 
atmosphere ; but animals that are not furnished with 
respiratory organs, are very nearly at the same tempera- 
ture with the medium in which they live. 

8. Among the hot animals, those are the warmest 
which have the largest respiratory organs ; consequent- 
ly breathe the greatest quantity of air in proportion to 
their bulk. 

Illustration. The respiratory organs of birds are great- 
er, in proportion to their bulk, than those of any 
other animals ; and birds are know r n to have the greatest 
degree of animal heat. 

9. From observations and experiments made by Dr. 
Crawford, it appears that the production of animal heat 
depends on a process analogous to chemical affinity^ and 
which is on the following principles. Oxygen gas con- 
tains more specific heat in proportion to its temperature 
and weight, than carbonic acid gas. The blood is re- 
turned to the lungs impregnated with the carbonaceous 
principle, but has less attraction for that principle than 
oxygen has. In the lungs, therefore, the Carbon quits 
the blood to unite with the oxygen which is inhaled 
from the atmosphere* By this combination, the oxygen 



TO CHEMISTRY, 873 

gas is changed into the carbonic acid gas, and deposits 
part of its heat. The capacity of blood for heat is, at 
the same time, increased ; the blood, therefore, receiv- 
ing that portion of heat which was detached from the 
air. 

10. The arterial blood in its passage through the ca- 
pillary vessels, is again impregnated with the carbon and 
the hydrogen, by which its capacity for heat declines ; 
it, therefore, in the course of the circulation, gradually 
gives out the heat which it had received in the lungs, 
and diffuses it over the whole bod}'. Thus it appears, 
that in its circulation through the lungs, the blood is 
continually discharging carbon and absorbing heat, and 
that in its passage through the other parts of the body, 
it is imbibing carbon and emitting heat. 

11. By the different capacities which blood possesses 
^for heat in its different states, it is capable of supplying 
the different parts of the body with warmth, while its 
own temperature remains the same. 

12. If this difference of capacity for caloric did not 
exist, the extremities of the body could not be properly 
supplied with heat from the lungs^ unless the lungs them- 
selves were exposed to a degree of heat, which would 
be prejudicial, and perhaps such as no organized being 
could support, without destruction. 

13. It has been proved, by a variety of experiments, 
that when an animal is placed in a cold medium, the ve- 
nous blood acquires a deeper hue, that a greater quan- 
tity of air is vitiated in a given time, consequently that 
more heat is absorbed by the blood. 

14. Perspiration prevents an accumulation of heat in 
the system beyond what is salutary ; if this be stopped., 
the heat increases. This is probably the principal cause 
of heat in fevers, the pores being closed there is no vent 

32 



374 "INTRODUCTION 

for the heat which is generated, which occasions 'those 
burning sensations. 

15. One of the most considerable secretions is insen- 
sible perspiration ; this is constantly conveying from the 
^body heat in its latent state. 

16. In violent exercise, the caloric is increased, but in 
a healthy person, it is carried off by the perspiration 
which succeeds. 

17. Inconsequence of the economy of perspiration, 
persons are enabled in all climates, and in all seasons, to 
preserve their bodies of an equal temperature, that is 
with regard to the blood -and the internal parts of the 
body ; for those parts of the body which are in immedi- 
ate contact with the atmosphere will occasionally be- 
come warmer or colder, than the internal or more shel- 
tered parts. But if the ball of a thermometer be applied 
under the tongue, it will be found to indicate scarcely 
any diiTerence in the stitte of the blood, whatever may 
be the changes in the atmosphere. 

Illustration. Persons have been known to remain some 
minutes in a heat little inferior to that of boiling water, 
without increasing in any great degree the internal heat 
of the system. In some instances, the heat Las been 
much greater than boiling water. 

PRACTICAL QUESTIONS. 

Is any heat disengaged during respiration ? 

Has venous and arterial blood the same capacity for 
heat? 

How is heat diffused through every part of the body ? 

Is the heat of animals the same at all times ? 

With regard to heat, how have animals been divided? 

What gradation do the human kind form in the class of 
hot animals ? 



TO CHEMISTRY. 3/5 

How is it with regard to quadrupeds ■■? 

What animals have the power of keeping their tem- 
perature above that of the atmosphere ? 

What animals are the warmest ? 

What is Dr. Crawford's theory of animal heat T 

What office does the arterial blood perform ? 

How does the blood supply the different parts of the 
body with heat while its temperature remains the same ? 

What is the effect of placing an animal in a cold me- 
dium ? 

What prevents a too great accumulation of heat in the 
system ? 

What is the cause of heat in fevers ? 

W r hat is one of the most important secretions ? 

Violent exercise increases heat ; does it not cause fe- 
ver ? 

How is it that persons in all climates and seasons ate 
capable of preserving an equality of temperature ? 



DICTIONARY OF TERMS, 
A. 

Absorption, the conversion of a gaseous fluid into a li- 
quid, or solid, on being united to another substance. 

Abstraction, a term, used to denote when an acid or 
other fluid is repeatedly poured upon any substance and 
distilled off, with a view to change the state or composi- 
tion. : 

Acerates, salts formed by the union of aceric acid with 
a base. 

Aceric acid, a substance obtained from the juice of the 
maple, having acid properties. 

Acescent, a term applied to those substances which be- 
come sour spontaneously. 

Acetates, substances formed by the union of acetic acid 
with salifiable bases, 

Acetic acid, concentrated vinegar: 

Acetous, of, or belonging to vinegar. 

Acid, a substance, which, when united with alkalies, 
earths ajid metallic oxides, forms salts. 

Acidifiable, capable of being converted into an acid. 

Acidules, a term applied by the French chemists to > 
those salts w T hich we denominate by the term bi, or sup- 
per. 

Adhesion. See cohesion. 

Adopter, a vessel with two necks placed between a re- 
tort and receiver, to increase the length of (he former. 
32* 



373 INTRODUCTION 

Aerial acid. Carbonic acid. 

Aerometer, an instrument for ascertaining the mean 
bulk of the gases. 

Affinity. See attraction. 

Agaricus, the mushroom, a genus of the order Fungi. 

Agaricus mineralis, one of the purest species of carbo- 
nate of lime. 

Aggregate. When two bodies are united together, the 
mass is called an aggregate, and preserves the chemical 
properties of its constituents. 

Air. the permanently elastic fluid which surrounds the 
globe ; the term is now exclusively confined \o the at- 
mosphere ; that of gas to other invisible and elastic 
fluids. 

Alabaster, sulphate of lime. 

Albumen, the white of egg, and one of the constituent 
principles of all animal solids. 

Alburnum, the inner white bark of trees. 

Alcohol, a term applied to pure spirit. 

Alembic, a still. 

Alkahest, the pretended universal solvent of the an- 
cients. 

Alkali, a term derived from the word kali, the Arabic 
name of a plant, from the ashes of which, one species of 
alkaline substances may be obtained. 

Alkalescent, any substance in which alkaline proper- 
ties are beginning to be developed. 

Alloy. When an inferior metal is added to a precious 
one, the part added is called the alloy. Thus when cop- 
per is tMed to gold, the former is the alloy. 

Aludel, a vessel used in sublimation. 

Alum. Sulphate of alumina. 

Alumina, one of the primitive earths, constituting the 
plastic principle of all clays, loams, fee. 



TO CHEMISTRY. 379 

Acetate of alumina, a combination of acetic acid with a 
salifiable base. 

Amalgam, a combination of mercury with other metal- 
lic substances. * 

Amber r a hard, brittle, tasteless substance, sometimes 
perfectly transparent, but mostly semi-transparent, or 
opaque, and of a glossy surface. It is chiefly of a yel- 
low or orange colour. 

Ammonia, volatile alkali, a substance prepared from 
animal matter ; its constituents are hydrogen and nitro- 
gen. When pure, it is an invisible gas, having a very 
pungent odour. 

Analysis^ the art of separating the constituents of bod- 
ies, so as to discover their properties. 

Anhydrous, a term applied to salts when destitute of 
water. 

Antimony, a word used in commerce, to denote a me- 
tallic ore, consisting of sulphur combined with the met- 
al. The latter is properly called metal by chemists. 

Apyrous. Bodies which sustain the action of a strong 
heat for a length of time, without change of figure or 
other properties, have been called apyrous, or refracto- 
ry* 

Aqna foriis, a name given to an impure and weak ni- 
tric acid, commonly used in the arts. 

Aqua regia, so named from its property of dissolving 
gold, now called nitro-muriatic acid. 

Aqua xiiae. Spirit of the first distillation ; the distil- 
lers call it, low wines. 

Archil, a species of moss growing upon rocks in the 
Cape Verd and Canary Islands, of which a rich purple 
tincture is made. % 

Aromatics, plants which possess a fragrant smell, united 
with pungency, and at the same time are warm to the 
taste, ars aromatics. 



380 INTRODUCTION 

Arsenic, a metal of a bluish white colour, subject to 
tarnish, and turns first yellowish, then black, on expo- 
sure to the air. It sublimes in close vessels, and burns 
with a small flame, if oxygen be present. 

Athanor, a furnace used by ancient chemists ; now fal- 
len into disuse. 

Atmometer, an instrnment to measure the degree of 
exhalation from a humid surface in a given time. 

Atmosphere, the invisible elastic fluid which surrounds 
the earth. 

Atropa, a poisonous vegetable principle, probably alka- 
line, lately extracted from the Atropa Belladonna, or 
deadly night shade. 

Attraction, the tendency which bodies possess to ap- 
proach each other. 

Aurum Musivum, a combination of tin and sulphur, the 
bi-sulphuret of tin. 

Azote. Nitrogen gas. 

B. 

Balloon, a glass receiver of a spherical form. 

Balsams, substances of a resinous nature, which spon<= 
taneously become concrete, and are capable of affording 
benzoic acid when heated alone, or with water. 

Balsam of sulphur, a solution of sulphur in oil. 

Baldwin's phosphorus, ignited nitrate of lime. 

Barium, the metallic basis of the earth barytcs. 

Barilla, a term given in commerce to the impure soda, 
imported from Spain and the Levant. 

Barolite. Carbonate of barytes. 

Base, or basis, a chemical term usually applied to al- 
kalies, earths and metallic oxides, in their relation to 
acids and salts. It is sometimes also applied to the par- 
ticular constituents of an acid or an oxicle. on the suppo- 



TO CHEMISTRY. 38 J* 

sition that the substance combined with the oxygen, &c* 
is the basis of the compound to which it owes its particu- 
lar qualities. 

Bath, a vessel partly filled with sand, water, or some 
other substance, in order to produce a uniform heat to- 
retorts and other glass vessels, in some operations. 

Beer, a liquor made of malt and hops. 

Bell metal, a composition of tin and copper. 

Benzoic acid, an acid obtained from Benzoin. 

Bi, a term used to express an excess of some ingredi- 
ent in many chemical compositions. 

Bile, a bitter liquid of a yellowish colour, the peculiar- 
secretion of the liver of some animals. 

Bismuth, a metal of a yellowish or reddish white col- 
our, little subject to Ghange in the air j somewhat harder 
than lead, and very little malleable. 

Bistre, a brown pigment consisting of the finer parts of 
wood soot, separated from the grosser by washing. 

Bittern, the water which remains after the crystalliza*- 
lion of common salt in sea water, or the water of salt 
springs. It abounds with sulphate and muriate of 
lime. 

Bitumen, this term includes a number of inflammable 
mineral substances burning with flame in the open air, 
such as Naphtha, Petroleum, Barbadoes tar, &c. 

Black Jack, an ore of zinc. 

Black Lead, Plumbago. 

Black Wadd, an ore of manganese. 

Bleaching, a chemical art by which the various articles 
used for clothing are deprived of their natural dark col- 
our, and rendered white. 

Blende, an ore of zinc. 

Boron, the combustible basis of boracic acid, 

Brandy, a spirit distilled from wine. 



^8%; INTRODUCTION 

Brass i a compound metal consisting of copper combined;: 
with about one third of its weight of zinc. 

Brimstone, Sulphur, . 

Bronze, a mixed metal, consisting chiefly of ccpper,with. 
a small proportion of tin, and sometimes other med- 
als. 

Brucine, a new vegetable alkali, lately extracted from 

the bark of the false angustura. Brycea antidysen- ~ 
terica. 

Brunswick green, an ammoniaco-muriate of copper^ 
used as a pigment. 

Butters of the metals, now called chlorides 

c. 

Cadmium, a new metal, discovered in 1817, in a car- 
bonate of zinc, and the silicates of zinc. The name was 
formerly applied to zinc. 

Caffein, a name given to a substance obtained from un- 
soasted coffee. 

Cajeput oily a volatile oil obtained from the leaves of 
the eajeput tree. 

Calamine, a native carbonate of zinc. 

Calcareous, partaking of the nature of lime, 

Calcareous spar, crystallized carbonate of lime. 

Calcination. The fixed residues of such matters as-? 
have undergone combustion, are called cinders in com- 
mon language, and calces or oxides, by chemists; the op- 
eration when considered with regard, to these, calci- 
nation. 

Calcium, the metallic basis of lime. 

Calculus, a name usually given to all hard concretions 
not partaking of bone, formed in the bodies of ani- 
mals, 



""TO tHEMlSTRlr-. 

*C?doric, the matter of heat, or the agent to which the 
phenomena of heat and combustion are applied. 

Calorimeter. An instrument contrived to measure the 
heat given- out from bodies in cooling-, from the quantity 
of ice it melts. 

Cameleon Mineral. When pure potash and black oxide 
of manganese are fused together in a crucible, a com- 
pound is obtained, whose solution in water,at first green, 
passes spontaneously through the whole series of colour- 
ed rays to the red; from this cirumstance the name ca- 
meleon has been given to it, 

Carbon, the pure inflammable part of charcoal, or the 
diamond. 

Carbonates, compounds of carbonic acid with salifiable 
leases. 

Carburets, compounds of carbon with any other sub- 
stance, as carburet of iron, steel. 

Carmine, a red pigment prepared from cochineal. 

Caromel. The smell exhaled from burnt sugar. 

Case hardening, when the surface of iron is converted 
to steel by being inclosed m a box with animal or vege- 
table charcoal, and subjected to the heat of a forge. 

Causticity, the power which some bodies possess to 
combine with the principle of organized substances, 
so rapidly as to destroy the parts, 

Cement. Whatever is employed to unite things of the 
same, or of different kinds ; as lute, glue, solder, &c. 

Cementation, a chemical process which consists in sur- 
rounding a body in the solid state, with the powder of 
some other bodies, and exposing the whole for a time in 
a closed vessel, to a degree of heat net sufficient to fuse 
the contents. 

Cerasin, a name given to the gummy substances which 
swell in cold water, but do not readily dissolve in it 



'384 INTRODUCTION 

Cerin, a peculiar substance which precipitates on evap- 
oration from alcohol, which has been digested on grated 
cork. The term is also applied to common wax which 
dissolves in alcohol. 

Cerium^ the name of a metal found in cerite, a mineral 
of Sweden. 

Ceruse. Subcarbonate of lead. 

Celine. Spermaceti. 

Chalk. Carbonate of lime. 

Charcoal, the residuum of vegetable substances burnt 
in close vessels. 

Chlorates, compounds of the chloric acid with salifia- 
ble bases. 

Chlorides, compounds of chlorine with combustible bod- 
ies. 

Chlorine, a simple substance, the base of what was for- 
merly called oxymuriatic acid gas. 

Chhrophyle, the green matter of the leaves of 
plants. 

Chromium, the name of a metal extracted from the na* 
tive chromate of lead or iron. 

Cinchonin, a substance obtained from cinchona or the 
peruvian bark. 

Cinnabar. Mercury united to sulphur. 

Cistic oxide, a variety of urinary calculi. 

Citric acid, the acid obtained from limes and lerft- 
ons. 

Clarification, The process of freeing a fluid frcm he- 
terogeneous matters. 

Clay, aplastic sub&tance whose basis is alumina. 

Coake, the residuum of the combustion of coals in clos<? 
vessels. 

Coal, an inflammable mineral substance well known. 

Coal-gas. Carburetted hydrogen, 



TO CHEMISTRY'. SuO 

Coating, a substance applied to the bottom of retorts t 
defend them from the too great action of heat. 

Cobalt, a brittle, somewhat soft, but difficultly fusible 
metal of a reddish grey colour and of little lustre ; so cal- 
led from Cob aim, the demon of mines. 

Cochnillui, the red colouring* matter of cochenenl. 

Cohesion, that power by which the particles of bodies 
are held together. 

CohobatioU) redistillation of the same liquid from the 
same materials. 

Colccihar. The brown red oxide of iron, which re- 
mains after distilling the acid from sulphate of iron. 

Cold. The privation of heat. 

Columbium, a metal of a dark grey colour, resembling 
in lustre iron. 

Combination. The intimate union of the particles of 
different substances by chemical attraction, so as to 
form a compound possessed of new and peculiar proper- 
ties. 

Combustible, a body which in its rapid union with others, 
causes a disengagement of heat and light. 

Combustion. The disengagement of heat and light 
which accompanies chemical combinations. 

Congelation, the abstraction of heat from bodies, in such 
quantities as to cause them to assume solid forms. 

Copper, a metal of a peculiar reddish brown colour, 
hard, sonorous, very malleable and ductile, and of con- 
siderable tenacit}^. 

Copperas. Sulphate of iron. 

Corrosive sublimate, perchloride of mercury. 

Cream of tartar, bitartrate of potash. 

Crocus Martis. The reddish yellow oxide of iron. 

Cyrophorus, an instrument invented to demonstrate the 
33 



386 INTRODUCTION 

relation between evaporation at low temperatures, and 
the production of cold. 

Crystal, a regular geometrical figure,formed when flu- 
id substances are suffered to pass w r ith adequate slowness 
to the solid state. 

Cupel, a shallow earthen vessel resembling a cup, 
made of bone ashes and used in assaying. 

Cupellation. The refining of gold by scorification with 
lead on a cupel. 

Cyanogen. The compound base of prussic acid. Now 
called Prussine, 

D. 

Daphnin, the bitter principle of Daphne Alpina. 

Datura, a vegetable alkali obtained from Datura Stra- 
monium. 

Dccantation, the act of pouring off the clear liquor from 
a precipitate or sediment. 

Decoction, the operation of boiling. The term is also 
used to denote the product of the operation itself. 

Decomposition, the separating of the component parts 
ar principles of a substance. 

Dccrepicanon. The crackling noise which several 
salts make when suddenly heated, accompanied with a 
violent exfoliation of their particles. 

Delphiiiia, a vegetable alkali dicovered in Staves- 
acre. 

Deliquescence, the spontaneous assumption of the fluid 
state by certain saline substances when left exposed to 
tiie air, in consequence of their affinity for water. 

Dephlegtnaiion, any method by which bodies are depriv- 
ed of water, 



TO CHEMISTRY. 387 

Dephlogisticated, deprived of phiogistion or the inflam- 
mable principle. 

Dephlogisticated air. The same with oxygen gas. 

Derbyshire spar, fluate of lime. 

Destructive Distillation, is when a substance is exposed 
to distillation, until it has undergone the whole power of 
the furnace. 

Detonation, a sudden combustion and explosion. 

Dew, the moisture insensibly deposited on the surface 
of the earth, from the atmosphere. 

Digestion, the slow action of a solvent upon any sub- 
stance. 

Digestive salt, muriate of potash. 

Digester, a vessel invented to prevent the loss of heat 
by evaporation ; by which the solvent power of water is 
greatly increased. 

Distillation. The vaporization and subsequent conden- 
sation of a liquid, by means of an alembic, or still and re- 
frigeratory; or of a retort and receiver. 

Docimastic Art, the art of assaying metals. 

Dragon's blood, a brittle dark coloured resin, imported 
from the East Indies. 

Ductility, that property or texture of bodies, which 
renders them capable of being drawn out in length, while 
their thickness is diminished ; this term is almost exclu- 
sively applied to metals. 

Dyeing, the art of fixing upon cloth of various kinds any 
colour, in such a manner as that they shall not be easily 
altered by those agents to which the cloth maybe expos- 
ed. 

E. 

Edulcoration. The purification of a substance by 
washing with water. 



INTRODUCTION 



Effervescence,ihe commotion produced in fluids by some 
part of the mass suddenly taking the elastic form and es- 
caping in numerous bubbles. 

Efflorescence, the effect which takes place when bodies 
spontaneously become converted into a dry powder. It 
is almost always occasioned by the loss of the water o* 
crystallization in saline bodies, 

Elain, the only principle of solid fats. 

Electricity, so named from electron amber, a simple 
substance supposed to pervade all nature. 

Eliquaiion, an operation whereby one substance is 
separated from another by fusion. 

Elutriation. the process of washing, by which the light- 
er parts are carried off, while the heavier metallic ones 
subside to the bottom. 

Emetin, a substance prepared from ipecacuanha 
root. 

Emulsion, an imperfect combination of oil and 
water. 

EmpyrcurrM, a peculiar disagreeable smell arising from 
the burning of animal matters in close vessels. 

Epidermis, when used with respect to animals, the 
scarf skin, with respect to vegetables the external cover- 
ing of the bark. 

Epsom salt. Sulphate of magnesia. 

Equivalents, a term used to express the system of atoms 
or definite proportions. 

Essences. Solutions of volatile oils in alcohol. 

Ether, a very volatile fluid produced by the distillation 
of alcohol with an acid. 

Eihiops mineral. Protosulphuret of mercury. 

Evaporation, a chemical operation usually performed 
by applying heat to any compound substance in order to 
dispel the volatile parts. 



TO CHEMISTRY. 339 

Extract, is a term used to denote the substance of the 
consistence of a paste, obtained b}' decoction of some veg- 
etable substance. 



Fecula, Starch. 

Fermentation, an internal motion in fluids by which 
they undergo spontaneous changes ; and carbonic acid is 
disengaged. 

Ferrocyanates, combinations of ferroprussic acid with 
salifiable basis 

Ferruretted Chyazic Acid, ferroprussic acid. 

Fribrin, a peculiar organic compound found both in 
vegetables and animals. 

Filtration, an operation by means of which a fluid is 
mechanically separated from particles mixed with it. 

Firedamp, carburetted hj^drogen. 

Fixed air, carbonic acid gas. 

Fixity, the property by which bodies resist the action 
of heat, so as not to rise in vapour. 

Flake white, the oxide of bismuth. 

Flowers, an old term used to signify all those bodies 
that have received a pulverulent form by sublima- 
tion. 

Filiates, compounds of the salifiable bases w T ith fluoric 
acid. 

Fluidity, the state of bodies when their parts are very 
readily moveable in all directions with respect to each 
other 

Fluoborates, compounds of the fluoboric acid with the 
"salifiable bases. 

Fluor, fluate of lime, or Derbyshire spar. 

Fluorine, the radicle of the fluoric acid. 
' 33* 



390 INTRODUCTION 

Flux, a substance, or mixture added to assist the fusion 
of metals. 

Formiaies, compounds of the formic acid with salifiable 
bases. 

Fuligenous. Vapours which possess the quantity of 
smoke. 

Fulmhiation. Thundering or explosion with noise. 

F ungates, compounds of the fungic acid with salifiable 
bases. 

FimgWi a substance obtained from mushrooms. 

Fusibility, that property by which bodies attain the 
fluid state. 

Fusion, the act of fusion ; also the state of a fused 
body. 

G. 

Galena, the black ore of lead. 

Gall of animals. Bile. 

Gallates. Salts formed by the combination of any base 
with gallic acid. 

Galls, the protuberances formed by the puncture of 
an insect en plants and trees of different kinds. 

Galvanism, the chemical action of bodies on each other. 
It is a method of exciting electricity or disturbing the 
equilibrium of the electrical fluid. 

Gamboge, a concrete vegetable juice, partly of a gum- 
my and partly of a resinous nature. 

Gangue, the stones which fill the cavities, that form 
the veins of metals, are called the gangue, or matrix of 
the ore. 

Gas, a name given to all permanently elastic fluids, 
simple or compound, except the atmosphere, to which 
term air is appropriated. 

Gelatine, a chemical term for animal jelly. 



TO CHEMISTRY. 39 i 

Geology, a description of the structure of the earth. 

Glauber's salt. Sulphate of soda. 

Glimmer, a name occasionally applied to micacious 
earths. 

Glucina, one of the ten substances known by the name 
of earths. 

Gluten, a vegetable substance somewhat similar to ani- 
mal gelatine. 

Gold, the most precious of all metals, of a yellow col- 
our, specific gravity 19.3. 

Goulard's Extract, a saturated solution of subacetate 
oflead. 

Granulation, the operation of pouring a melted metal 
into water, in order to divide it into small particles for 
chemical purposes 

Gravity, that property by which bodies move towards 
each other in proportion to their respective quantities of 
matter. 

Gum, the mucilage of vegetables. 

Gum Elastic. Caoutchouc. 

Gunfiowder, a substance well known, it consists of 75 
parts by w T eight of nitre, 16 of charcoal and 8 of sulphur, 
intimately mixed together. 

H. 

Heat. Caloric. 

Hematin, the colouring principle of logwood. 

Hefiar Sulfihuris, a name given to alkaline and earthy 
sulphurets, from their liver brown colour. 

Hefiatic gas, an old name for sulphuretted hydro- 
gen. 

Hermetically, a term applied to the closing of the 



392 INTRODUCTION 

orifice of a glass tube, so as to render it air tight 
Hydrogen, one of the constituent parts of water. 
Hydrocarbonates, combinations of carbon with hydro- 
gen. 

Hytieroxygenized, a term formerly applied to substan- 
ces which are charged with the largest quantity of oxy* 
gen. 

J. &L 

Jargon, see zircon. 

Icthyocolla. Fish glue, or isinglass. 

Ice. The natural state of water, or water in its 
crystallized form. 

Incineration, the burning of vegetables for their 
ashes. 

Indigo, a blue colouring matter, extracted from a plant 
called Aral. 

Indigo-gene, the colouring principle of indigo. 

Ink, a liquid used for writing or printing. 

Insolation, a term sometimes used to denote that expo- 
sure to the sun, which is made in order to promote the 
chemical union of one substance with another. 

Interme diates a term used when speaking of chemical 
affinity. 

Iodine, anundecompounded principle. 

Irridium, a metal found in the ore of platinum. 

Iron, a metal well known, of a bluish white colour, of 
considerable hardness and elasticity. 

Isinglass, ichthyocolla, almost entirely composed of 
gelatine. 



TO CHEMISTRY. 39S 

K. 

Kaliy a genus of marine plants, which is burnt to pro- 
cure mineral alkali, by lixiviating the ashes. 
Kaolin, the Chinese name for porcelain claj r . 



Laboratory, a place fitted up for the performance of 
chemical operations. 

Lactates, compounds of lactic acid with salifiable ba- 
ses. 

Lacquer, solution of lac in alcohol. 

Lake, a species of colour formed by precipitating col- 
ouring matter with some earth or oxide, 

Lead, a white metal of a bluish tinge, very soft and 
flexible, not very tenacious, and incapable of being drawn 
into fine wire, though it is easily extended into thin, 
plates. 

Lens, a glass convex on both sides for concentrating 
the rays of the sun. 

Levigaiion, the mechanical process of grinding the 
parts of bodies to a fine paste, by rubbing the flat face of 
a stone, called a muller, upon a table or slate, called the 
stone. 

Lime, oxide of calcium, one of the primitive earths. 

Liquefaction, the change of a solid to the state of a 
fluid, by the absorption of caloric. 

Lithiaj a new alkali, discovered by Arfredson, in the 
laboratory of Berzelius. 

Lixiviatim, the application of water to the fixed resi- 
dues of bodies, for the purpose of extracting the saline 
part. 

Lixivium, a solution obtained by lixiviation. 

Lunar Caustic. Nitrate of silver, 



39& INTRODUCTION* 

Lute, a chemical term, used to express the cement forr 
joining of broken vessels, or two vessels together. . 

M; 

Maceralhn % the steeping of a body in cold liquor, 

Magistery, a term originally applied to precipitates. 

Magnesia, one of the primitive earths, possessed of a 
metallic basis, called magnesium* 

Malates, salts formed by the composition of malic acid 
with a salifiable basis. 

Malleability, the power of being extended under the 
hammer. 

Maltha. Mineral tallow. 

Ma?iganese, a metal of a dull whitish colour when* 
broken, but which soon grows dark by oxidation, from 
the action of the air. 

Manures, animal and vegetable matters introduced in- 
to the soil, to accelerate vegetation, and increase the 
production of crops. 

Marble. Carbonate of lime. . 

Massicot, yellow oxide, or the deutoxide of lead. 

Matrix, the earthy or strong matters which accompany 
ores, or surround them in the earth. 

Mellates, compo unds of the mellitic acid with salifiable* 
bases. 

MefMtic gas. Carbonic acid. 

Menstruum, a word synonymous with solvent. 

Metallic oxides, metals combined with oxygen. 

Minium, the red oxide of lead, commonly called red 

lead. 

Mvrdants^ substances which have a chemical affinity. 

for vegetable colours. 

Mother Waters, or Mothers the liquors which are 

left after the crystallization of any salt. 



<T0 CHEMISTRY. SSt> 

Mvcites, salts formed by the combination of any base 
with the mucous acid. 

Mucus, one of the primary animal fluids, perfectly dis- 
tinct from gelatine. 

Muffle, a small earthen oven, to be fixed in a furnace 
for the purpose of cupellation. «. 

Must, the juice of grapes, composed of water, sugar, 
jelly, gluten, and bitartrate of potash. 

Myricin, the ingredient of wax which remains after 
.digestion in alcohoL 

N. 

Naphtha, a native combustible liquid, of a yellowish 
white colour, perfectly fluid and shining. 

Naples yellow, lead calcined with antimony and potash* 

Natron, native carbonate of soda. 

Neutralization, When acid and alkaline substances are 
added together in such proportions that the compound 
does not change the colour of litmus or violets, they are 
said to be neutralized. 

Nickel, a metal of great hardness, of uniform texture 
and colour, between silver and tin, it is said to be mag- 
netical. 

Nicotin, a peculiar principle obtained from tobacco. 

Nitraies, compounds of the nitric acid with the salifia- 
ble bases. 

Nitre, one of the names of nitrate of potash. 

Nitrogen, or azote, an important elementary or unde- 
-compounded principle. It constitutes four fifths of tl>r 
volume of atmospheric air. 

o. 

Oil of vitriol. Sulphuric acid. 
Olefiant gas. Carburetted hydrogen,- 



395 INTRODUCTION 

Opacity, the faculty of obstructing the passages o£ 
light. 

Ores. Bodies from which metals are extracted. 

Orphnent. Sulphuret of arsenic. 

Osmium, a metal discovered in the ore of platinum. 

Oxalates, compounds of oxalic acid with salifiable base? 

Oxidation, the process of converting metals, or other 
substances into oxides, by combining with them a certain 
portion of oxygen. 

Oxides, substances combined with oxygen^ without be- 
ing in the state of an acid. 

Oxygen gas. Vital air. 

Oxymuriatic acid. Chlorine. 

Oxyprussic acid. Chloro-prussic acid. 

p. 

Paste, glass made in imitation of gems. 

Pellicle, a thin skin which forms on the surface of sa- 
line solutions and other liquors, when boiled down to a 
certain strength. 

Phosphates, salts formed by the combination of any 
base with the phosphoric acid. 

Phosphorus of Baldwin. Ignited muriate of lime. 

Phosphorus of Canton. Oyster shells calcined with sul- 
phur. 

Phosphorus of Bologna. Sulphate of barytes. 

Phbsphuret, a compound of phosphorus with a combus- 
tible, or metallic oxide. 

Phlogisticatcd acid. Nitrogen. 

Phlogisticated alkali Ferroprussiate of potash. 

Phlogiston, inflammable principle of the old chemists* 

Picromel, the characteristic principle of bile. 

Picrotoxia, the bitter and poisonous principle of coccu* 
lus indicus. 

Pinchbeck, an alloy of copper. 



TO CHEMISTRY. 397 

Platina, one of the metals. 

Plumbago. Carburet of iron — black lead. 

Pneumatic. Any thing relating to the airs and gases*. 

Potash, the hydraied deutoxide of potassium. 

Potassium, the metallic base of potash. 

Potential cautery. Caustic potash. 

Prussiates, combinations of prussic acid with salifiable 
bases. 

Prussine, prussic gas, or cyanogen. The base of the 
prussic acid. 

Pyrites, native metallic sulphurets. 

Pyrometer, an instrument for measuring very high tem- 
peratures. 

Pyrophorus, a compound substance, which heats of it- 
self, and takes fire on the admission of atmospheric air. 

Quartation, is an operation by which the quantity of 
one thing is made equal to a fourth part of a quantity of 
another. 

Quartz, a name given to a variety of silicious earths, 
mixed with a small portion of lime or alumina, and gen- 
erally containing some metallic oxide. 

Quercitron. The bark of the yellow oak. 

Quicksilver. Mercury. 

R. 

Radical, that which is considered as the distinguishing 
part of an acid, by its union with the acidifying princi- 
ple, which is common to all acids. 

Rancidity, the change which oils undergo by exposure 
to the air. 

Re-agents, certain bodies used for detecting principles 
in solution. 

34 



;398 INTRODUCTION 

Realgar. Sulphuret of arsenic. 

Receivers, chemical vessels, which are adapted to the 
necks or beaks of retorts, into which the liquid when 
distilled is received. 

Reduction, or Revivification, the restoration of any sub- 
stance to its natural state, or which is considered as such ; 
it is usually applied to operations by which metals are 
restored to their natural state. 

Refrigeration. The act of cooling. 

Regulus, a term applied to metallic substances when 
separated from others by fusion. 

Respiration, a. function of animals, which consists in the 
alternate inhalation of a portion of air into an organ cal- 
led the lungs, and its subsequent exhalation. 

Retort, a vessel employed for many distillations, and 
most frequently for those which require a degree of 
heat superior to that of boiling water. 

Rhodium, a metal discovered among the grains of 
crude platinum. 

Rochelle salt. Tartrate of potash and soda. 

s. 

Sal Ammoniac. Muriate of ammonia. 

Sal Catharticus Amarus. Sulphate of magnesia. 

Sal Diureticus. Acetate of potash. 

Sal Glauberi. Sulphate of soda. 

Sal Martis. Green sulphate of iron. 

Sal Pohjchrest. Sulphate of potash. 

Salifiable Bases, the alkalies and those earths, and me- 
talic oxides, which have the power of neutralizing 
acidity, entirely or in part, and producing salts. 

Salt, the union of an acid with an alkali, earth, or me- 
talic oxide. 



TO CHEMISTRY . 39G 

Sanguification, that process of the animal economy by 
which chyle is converted into blood. 

Saponaceous, partaking of the nature of soap. 

Saturation. When a fluid holds as much of one sub- 
stance in solution as it can dissolve, it is said to be satu- 
rated. 

Selenium, a new elementary body, discovered by Ber- 
zelius, which he ranks between sulphur and tellurium. 

Sebat, a neutral compound of sebacio acid, with a base. 

Silica, one of the primitive earths. 

Silicon, the base of silica. 

Silver, the whitest of all metals, harder than gold, ve- 
ry ductile and malleable. 

Silvering, the art of covering metals and some other 
substances with a coating of silver. 

Soda. Mineral alkali 

Sodium. The base of soda; 

Solder, an alloy used for uniting metallic bodies to*- 
gather. 

Sorbates, compounds of sorbio acki, or malic, with the 
salifiable bases. 

Spelter, the commercial name for zinc. 

Starch, a -white insipid combustible substance, insolu- 
ble in cold w T ater 5 but forming a jelly with boiling water. 

Steatites, a mineral, composed of iron, silex and mag- 
nesia. 

Steel, a carburet of iron. 

Strontia, one of the substances usually called earths. 

Strontium. The metallic base of strontia. 

Strychnia, a vegetable alkali found in the strychmis mm 
vomica. 

Suber. Cork. 

Sublimation, a process by which volatile substances are 
raised by heat and again condensed in a solid form. 



100 INTRODUCTION 

Subsalt, a salt having an excess of base beyond whati& 
necessary for saturating the acid ; as supersalt is one with 
an excess of acid, the term bi is now more generally 
used. 

Succinates* compounds of succinic acid with a salifiable 
basis. 

Sugar of lead. Acetate of lead. 

Sulphates, definite compounds of sulphuric acid witk 
the salifiable bases. 

Sulphites, definite compounds of sulphurous acid witk 
the bases. 

Sulphuretted^ combined with sulphur. 

T. 

Tannin, one of the immediate principles of vegetables^ 
so called, from its use in tanning leather ; which is ef- 
fected by its characteristic property, that of forming 
with gelatine a tough insoluble matter. 

Tanning, the art of manufacturing skins into leather. 

Tantaliurn, one of the names of a metal commonly cal- 
led columbium. 

Tarras, or Terras, a volcanic earth used as a cement. 

Tartar, a substance deposited on the inside of casks 
during the fermentation of wine. 

Tartrate, a neutral compound of the tartaric acid with 
a base. 

Tellurium, a name given to a metal of a tin white col- 
our, verging to lead-grey, with a high metalic lustre ; 
found in Transylvania. 

Telluretted hydyrogen, a gas formed by a combination of 
tellurium and hydrogen. 

Temperature, a definite term of sensible heat as mea- 
sured by the thermometer. 

Terra, Japonica. Catechu. 



TO CHEMISTRY. 401 

Thermometer, an instrument for measuring heat, found- 
ed on the principle, that the expansions of matter are 
proportional to the augmentation of temperature. 

Thorina, an earth, discovered in 1816, by Berzelius, 
of Sweden. 

Thorinum, the supposed metalic basis of thorina, not 
hitherto extracted. 

Tin, a metal of a yellowish white colour, considerably 
harder than lead, scarcely at all sonorous, very mallea- 
ble, though not very tenacious. 

Titanium, one of the metals. 

Tombac, a white alloy of copper with arsenic, some* 
times called white copper. 

Touch stone, a variety of flinty slate. 

Tritorium, a vessel used for the separating of two flu- 
ids, which are of different densities. 

Trituration, a chemical operation whereby substances 
are disunited by friction. 

Tube of Safety, a tube open at both ends, inserted into" 
a receiver, the upper end communicating with the ex- 
ternal air, and the lower being immersed in water. It 
is to prevent injury from- too sudden condensation, or 
rarefaction, taking place during an operation. 

Tungsten, the name of a metal. 

Tungstates, salts formed by the combination of tungstie 
acid with salifiable bases. 

Turbeth Mineral, sub deutosulphate of mercury, 

u. 

Ulmin, a substance exuding from -the trunk of a specks 
of elm, the ulmus nigra. 

Uranium, The name of a metal. 

Urates, compounds of the uric or lithic acid with any 
base, 

34* 



402 INTRODUCTION 

Urea, a substance prepared from urine. 

Usiidation, the roasting of ores to separate the arse-, 
nic, sulphur, and whatever else is of a volatile nature, 
that is connected with and mineralizes the metal. When 
the matter which flies off is preserved, the process is 
called suhlimation, but when this matter is neglected, 
the process is called ustulation. 



Veratria, a new vegetable alkali, discovered in the 
veratrum album, white hellebore, and some other plants. 

Verdigris. Crude acetate of copper. 

Verditer, a blue pigment, obtained by adding chalk er 
whiting to a solution of copper in aqua fortis. 

Vermillion. The red sulphuret of mercury. 

Vinegar. Acetous acid. 

Vinegar from wood. Pyroiigneous acid. 

Vital dir. Oxygen. 

Vitrification. When certain mixtures of solid substan- 
ces are exposed to an intense heat, so aa to be fused and 
become glass, they are said to have undergone vitrifica- 
tion. 

Volatility, a property of some bodies which disposes 
them to assume the gaseous state. 

w. 

Wash, the technical term for the fermented liquor, of 
whatever kind, from which spirit is intended to be dis- 
tilled. 

Wax, an oily concrete matter, gathered by bees from 
plants. 

TVay, dry, a term used by chemical writers when treat- 
ing of analysis or decomposition- 



TO CHLMiSTR?. 403 

Way, humid, a term used in the same manner as the 
above, but expressive of decomposition in a fluid state. 
Whiting. Chalk cleared of its grosser impurities. 
Wodanium, the name of a recently discovered metal 



Yitria, a name of one of the earths. 

z. 

Zaffire, the residuum of cobalt, after the sulphur^ ar 
senic,and other volatile matters of the mineral have been 
expelled by calcination. 

Zero, the commencement of the scale of a thermome- 
ter marked 0. Thus we say, the zero of Farenheit, 
which is 32° below the melting point of ice, the zero of 
the centigrade scale which coincides with the freezing 
of water. The absolute zero is the imaginary point 
in the scale of temperature, when the whole heat is ex- 
hausted, the term of absolute cold, or privation of ca- 
loric ; this has never been ascertained. 

Zimome, the gluten of wheat, treated by alcohol, it is 
reduced to the third part of its bulk, 

Zinc, a metal of a bluish white colour, somewhat light- 
er than lead. 

Zircon, an earth found in the jargon of Ceylon. 

Zumates, combinations of the zumic acid with the sali- 
fiable bases, 



INDEX. 



A. 

Aceric acid, . . . . • Ite 

Acetic acid, . ik. 
Acidifiable metals, .... 237 

Acids, . . . . . 157 

classification of . . j • 159 

r of organic origin, . . . 192 

Aconita, . . . . . 303 

Affinity, ... .11 

Aggregate, . . . . .12 

Aggregation, . . . . ib. 

Albumen, .... 300 347 

Alcohol, ' . . .. . 312 316 

Alcohol of sulphur, . . . .95 

Alkalies, . . . . .111 

causticity of, . . 112. 

fixed, . , . ib, 

volatile, » ib. 

Alumina, . . . . .147 

Amber, .... . 325 

Amianthus, ...... 14? 

Ammonia, . . , * - 119 

Amniotic acid, . .193 

Animal heat, . . , 371 

Animal products, . . 345 

Animalization, .... 343 

Antimonious acid, . . . .182 

Antimonic acid r . . . .183 



406 INDEX. 

Antimony, . . J - • 2677 

Aphlagistic lamp, . * . 320 
Aqua Fortis, . . .• . .82 

Arrack, ..... 314 

Arsenic, . . • • • 273 

Arsenic acid, . . . . 181 

Arsenious, . , . . 367 

Arteries, ...... 367 

Asparagin, ..... 299 

Asphaltum, . . . .. 334 

Atomic theory, . . . . 21 

Atoms, ..... 22 

Attraction, . . * . .6 

Atropia, ^ .... 303 

Azote, ^ U 

B. 

Balsams, . 9 . . 301 

Barium, . . . . 138 

Barytes, . .. . . 136 

Benzoic acid, . . . . 193 

Bile, . 360 
Birdlime, .. . . .301 

Bismuth, ..... 266 

Bitter principle, .... 300 

Bitumens, . . • 324 

Black lead, . . . - 256 

Blood, , 349 356 

Blow pipe, . . . S9 

Boiling, ..... 65 

Boletic acid, . . . . . 193 

Bones^ . „ . «. 354 

Boracic acid r . . . . 162 



-INDEX. 407 

SBraia, . . . . . 361 

Brandy, . ... . 313 

Brass, . . . . . 254 

Bread, . . . ;-".-. 321 

Bricks, . .. . . . 149 

Brucia, . . . . . 303 

Butter of arsenic, . -. . . 274 
of bismuth, . 5 . , 267 

c. 

Cadmium, . . .. . . 262 

Caloric, . . . 43 57 69 

Calorific rays, .... 42 

Camphor, . • . . . 30l 

Camphoric acid, ... . 194 

Caoutchouc, . . . . 302 

Capacity for heat, . . . .69 

Carbon, ... ,. . 11 103 

Carbonates, . , . . 164 

Carbonic acid, . . . 105 106 162 

Carburetted hydrogea, . . . 88 107 

Caseicacid, . . . . 194 369 

Caseous matter, . . . . 348 

Causticity of alkalies, . . • 112 

Cements, , . . . .142 

Cerium, .... • 282 

Chalk, .... - HO 

Chameleon mineral, , * . 27 

Charcoal, . . . . .103 

Cheese, 369 

Chemical attraction, . ? . . .13 

Chemical equivalents, , . • 233 

Chemistry, , . , * 



•408 pci*. 

: Chest, - - - - 366 

Chicric acid, - 167 
Chloric oxi.de, * - - -211 

Chloride of sulphur. - 94 

Chlorine, - - - 205 
Chloro carboneous acid, - - - 169 

Chloro prussic acid, - - 189 

Chromic acid, - - - - 183 

Chromium, - 275 

Cicuta, - .... 303 

Citric acid, - 194 

Coa^ - - . . 325 

Cobalt, - 270 

Cocheneal, - 307 

Cohesion, 6 

Coke, - - - 325 

Cold, .... 50 

Colorific rays, --.... 42 

Colouring matter, a. 306 

of the blood. * 369 

Columhic acid, - - - 184 
Columbium, - - - - 287 
Combined caloric, - - - 44 61 69 

Combustion of sulphur, - - - 92 

Conductors of caloric, - - 57 

Copper, - - . . 251 

Cotton, ..... 302 
Craw ford's theory of animal heat, ... 372 

Crystallization, - 5 

of metals, * . 233 

Cyanogen, - m 



INDEX, 



403 



D. 



Datura, - 306 

Decomposition, - 14 

. of alkalies, - - -123 

of vegetables, - - 309 

of water, - - 84-107 



Delphinia, - - - - 303 

Deoxydizing rajs, - 42 



Dew, 



64 



Diamond, - - - - 1Q 4 

Diaphragm, - * - 366 

Diana's tree, ----- 24o 

Differential thermometer, - 48 

Digestion, (Pepins) - 

Digestion, ----- - 344 

Divisibility of matter, | - - 

Division of substances, - - - - 9 

Dry rot, 322 

Dyeing, - - - - 

E. 



307 



Earthern ware, - - - - - - 149 

Earths, 133 

found in plants, - - - - 134 

Elastic fluids, - - - - 49 

Electricity, - - * 22 ^ 

Electric attraction, - - - ' 

Elements, - - - - - 10 

Epidermis, - - - * 354 

Ether, - - - - 318 

Euchlorine, - - - 2l ^ 
35 



410 INDEX. 

Evaporation, ... 64 

Expansion of bodies, - 45 

Extractive matter, - - - - 300 

F. 

Fermentation, - 309 

Ferroprussic acid, - - - - 188 

Fixed air, - 105 

alkalies, . . . . 112 

oils, . . . . .301 

Flame, - 87 

Flowers of antimony, - - - - 182 

Flowers of bismuth, - - 266 

—of sulphur, - - - 91 

of zinc, . . . 262 

Fluate of lime, - - - - 12 186 

Fluoboric acid, . - - - 190 

Fluoric acid, - - - - 186 

Fluosilicic acid, - - - 154 190 

Freezing, - - - - 61 65 

of lakes, ... - 62 

Fuller's earth, - - - - 154 

Fungic acid, ... . . - 194 

Fungin, ... - 302 

Fusion of metals, 63 

G. 

Galena, - - - 261 

Gallic acid, - - ? -- 195 

Galvanism, - - - 224 

Gaslights, - - - .88 

Gastric juice, • • - 362 

Gelatine, . - - 345 346 



INDEX. 411 

Germination, - - - - 333 

Gin, - - - - - 314 

Glass, - - - 115 

of antimony, - - - - 263 

Glazing, - - - - 149 

Glucina, - - - - 151 

Glue, - - - 346 

Gluten, - _ . . 300 

Gold. - - - 241 

Goulard's extract, - - - 261 

Gravitation, - - - 6 

Guaiacum, - 301 

Gum, ... 299 

Gypsum, -• - - - 14 

H. 

Hartshorn, - 120 

Heat, -.--- 44 

of capacity, - - - 70 

latent, - - 69 71 

Heart, - 36-7 

Heat of the human body, . . 372 

Hematin, - - - 392 

Hydrate of potash, - - 113 

Hydriodic acid, - - - 187 

Hydrogen. - - - - S3 

gas, combustion of - - - 36 

how obtained, - - - 84 

' acids, - 186 

Hydroguretled sulphuret o f ammonia, - 120 

Hydrochlorides, - - - 167 

Hydrosuiphurous acid, - - - 188 

Hyosciarna, - - - - 304 

Hyp ophosphorous acid. - - - lit 



412 IKDEX. 



Hyposulphurous acid, - 1?2 

Hyposulphuric acid, - - - ^^ 



i. 



Ignition, 


- 


Impenetrability, 


- 


Indigo, 


- 


Ink, 


- 


Instruments for measuring heat 


Inulin, 


- 


Iodic acid, 


- 


Iodides, 


- 


Iodine, 


- 


Iridium, 


- 


Iron, 


- 


cold short, 


- 


protoxide of 


- 


Iron mould, 


- 


Isinglass, 


- 




J. 


James' powder, 


- 


Jelly, 


- 


Jet, 


- 




K. 


Kermes mineral, 


- 


Kinic acid, 


- 




L. 


Laccic acid, 


. 


Lactic acid, 


— — 



66 

2 

300 

255 

45 
299 
171 
215 
213 
281 
254 
101 

76 
256 
346 



269 
349 
325 



268 
- 195 



195 
196 



IXDEX ' 413 

Lakes, freezing of - ■■ - .- C2 

Lampic acid, - - - - 196 

Lapis calaminaris, - 262 

Law of Berzelius, - - - - 18 

ofRichter, - - - 25 

Laws ef affinity, - - - - IS 

Lead, 259 

Leathery - ■- - - 346 354 

Light, ' -■ . . - - 33 

Lime, - - - - - 130 

Lime water, - - - - - 140 

Liquor of Libavins, t - - 203 

Litharge, - - - - 259 

Lithia, - - » : 117 

Lithic acid, -- - - - *96 

Liver of sulphur, - - - - 115 

Luna cornea, - 243 

Lunar caustic, - - - - -' 244 

Lungs, ...... 366 

BE 

Majesiery of bismuth, - ■ - - ■ 267 

Magnesia, - - " .145 

Magnesium, - - - - 147 

Magnetic attraction, - 

Manganese, - ~ u ' 

Margaric acid, - - - - - " 197 

Malic acid, - -- - " " ' 1Di 

Manure, - - - ' 323 
Matter, - 

Meconic acid, - - - 197 

Medulla oblongata, » - - - - 362 

Melascic acid, - - - * i97 
aft* 



414 INDEX. 

Mellitic acid, - - - - - - 198 

Mercury, - - - 247 

Menispermic acid, - - - - 197 

Metallic acids, . - - 181 

Metals, . . . . . 235 

Mineral tar, , . . 325 

pitch, . . . ibid 

Mixtures, . . . .12 

Mobility, . . 3 

Molybdenum, - - - 276 

Molybdic acid, - - - 184 

Molybdous acid, - - - ibid 

Momentum, - - - 6 

Mordants, ... 308 

Moroxylic acid, - - 198 

Morphia, - - - - 304 

Motion, ----- 4 

Mucic acid, - - 198 
Mucus, - ... 350 

Muriates, - 167 

of ammonia, - - - 120 

Muscles, - - - - 353 

N. 

Naptha, - 329 

Neutral salts, - - - - 112 

Nickel, - - - - - 261 

Nitrate of potash, - - - 46 

Nitric acid, ... - 32 

Nitrogen, ----- go 

properties of - - 81 

uses of - - 80 

Nitrous acid. - - - - 169 



INDEX, 415 

o. 



Oils, 

Oleic acid, 

Organised bodies, 

Orpiment, 

Osmazome, 

Osmium, 

Oxalic acid, 

Oxides, 

Oxygen, 

properties of 

Oxygen acids, 
Oxyhydrogen blow pipe^ 
Oxymuriatic acid, 



Palladium, 
Parenchyma, 
Particles of light, 
Peat, 

Perchloric acid, 
Petroleum, 
Pewter, 
Phosgene gas, 
Phosphorescent, 
Phosphoric acid, 
Phosphorous acid, 
Phosphuretted hydrogen, 
Phosphorus, 
combustion of 



Picromel, 

Picrotoxia, 

Platinum, 



- v 


lUtf 


- 


198 


- 


297 


- 


274 


- 


351 


- 


278 




199 


77 


78 


- 


74 


- 


75 


• 


181 


- 


89 


- 


205 




246 


- 


332 


- 


39 


135 


336 


- 


168 




325 


- 


267 




169 




40 


98 


172 


99 


171 


- 


89 


11 97 


101 


98 


100 


- 


351 




304 




238 



41 D 



IXDEX. 



Plaister of Paris, 

Plumbago, 

Plumula, 

Polienin, 

Porcelain, 

Potash, 

Potassium, 

Potential cautery, 

Pot metal, 

Principles of radiation, 

Prussian blue, 

Prussic acid, 

Prussine, 

Puzzolkino. 

Pyroligneous acid. 

Pyrolithic acid, 

Pyromalic acid, 

Pvrctariaric acid. 



108 



14 

256 
333 
303 
149 
113 
124 
114 
254 
53 
352 
177 
28 i 
143 
32! 
200 
ibid 
ibid 



Quicksilver, 



Q. 



:-n 



R. 



Radiation, 



principles of 

Rays of light, 

Re algar, 

Refrigerators, 

Regulus of antimony, 

Resin, 

Respiration, 

Rhodium, 

Rock crystal, 



50 
53 

39 
274 
10S 
2G8 
301 
365 
280 
153 



INDEX. 



417 



Rosacic acid, . - • .201 

Rum, • • - 314 

S. 

Sal ammoniac, . . - • • - * 2 ^ 

Salt of tartar, , • • m 

Saltpetre, U6 

Salts, 



Size, 
Skin, 



211 



Sarcocol, ' • - ^99 

Saturation, . . • ^ 

Sebacic acid, - • ^ 201 

Selenium, v . • • 2^7 

Selenic acid, . » • 278 



152 



Silica, ... 

Silver, . . , • ^43 



346 
354 



Slacked lime, ■ ■ • 161 

Soda, 

Sodium, . 

Solidity, . . - 

Sorbic acid, . 

Sources of light, 

Specific caloric, 

Speculum metal, - 

Starch, 

Steel, - 

Strontian, - 

Strychnia, -. 

Suber, - 

Suberic acid, - - " ^* 

Substance, * ' - 

Succinic acid, - - - %®~ 



116 

129 

2 

201 

43 

70 

254 

299 

108 

138 

304 

302 



164 



INDEX. 



Sugar, 



of diabetes, 
of lead, 
of milk, 



Sulphate of lime, 
Sulpho cyanic acid, 
Sulpho vinic acid, 
Sulphur, 

combination of 

combustion of 

uses of 

Sulphurets, 
Sulphuret of potash, 
Sulphuretted hydrogen, 
Sulphuretted chyazic acid, 
Sulphuric acid, 
Sulphurous acid, 
Super saturation, 
Sympathetic ink, .. . 



299 

352 

260 

349 

14 

94 

202 

91 

92 

ibid 

96 

93 

115 

89 

94 

174 

173 

217 

271 



T. 



Talc, 
Tallow, 

Tannin, 
Tantalium, 

Tarras, 
Tartar emetic, 
Tartaric acid, 
Tellurium, 

Telluretted hydrogen. 
Thermometer, 
Theory of caloric. 
Thorina. 



149 

108 
301 

277 
143 
269 
202 
271 
ibid 
46 
50 
154 



INDEX. 



419 



257 
ib. 
282 
217 
27G 



Tin, . • ... 

. foil, .... 

Titanium, ■• 

Triple salts, .... 

Tungsten, . 

Tungstic acid, . * • 184 

Turf, . • • ^ 326 

u. 

Ulmin, • • 299 

Uncombined caloric, ..... 49 

Uranium, . . . • 281 

Urea, . . -.' ■ • ^0 

Urine, ... • 357 



Vaporization, . 64 

Vegetables, -* . ■.. . - 297 

Vegetation, . » • . .328 

Veins, . : . . . .367 

Velocity, . ... .5 

Veratria, . . . 304 

Verdigris, * 253 

Vinegar, . . . . . 320 

Volatile alkali, . . . , 112 119 

— oils, ..... 301 

Volumes, ..... 27 

Voltaism, ..... 224 

w. 

Water, freezing of . . , .62 

Wax, . . t 108 301 



420 INDEX* 

Whiskey, . . . . -, 364 

White lead, • , . . .259 

White vitriol, .... 263 

Wodanium, . • . 283 

Wood, . 302 



Yttria, . . . ' . . . . .151 

z. 

Zinc, 262 

Zirconia, ....... 152 

Zumic acid, . . 202 



H 296 83 ■* 










»"' ^ 




• . » * A -^ 



A*" ^VP^ ^ ^ ^fA°o ^ A* ^ 




rf 



V ^i^ % '** 











v<0 









°o 
















, " " « ♦ "•*>. 




1* *T 




^ 




:* ^ 













*^ 











v* -ill*- w -A-. v •• 



J \ 



+*. 









w 
















^ .*» .-vaty-. ■ % ./ ..^-. %/■ .■ 




i 



^ NOV 83 



N. MANCHESTER, 
INDIANA 46962 



:►"*♦♦ •' 











